Filed pursuant to Rule 424(b)(5)
Registration No.: 333-220777

The information in this preliminary prospectus supplement and the accompanying prospectus is not complete and may be changed. A registration statement relating to the notes has become effective under the Securities Act of 1933, as amended. This preliminary prospectus supplement is not an offer to sell the notes and it is not soliciting an offer to buy the notes in any jurisdiction where the offer or sale is not permitted.

Subject to Completion, dated November 14, 2017

PRELIMINARY PROSPECTUS SUPPLEMENT

(To Prospectus dated October 13, 2017)

$100,000,000

Everbridge, Inc.

    % Convertible Senior Notes due 2022

We are offering $100,000,000 principal amount of our     % Convertible Senior Notes due 2022. The notes will bear interest at a rate of     % per year, payable semiannually in arrears on May 1 and November 1 of each year, beginning on May 1, 2018. The notes will mature on November 1, 2022.

Holders may convert their notes at their option at any time prior to the close of business on the business day immediately preceding May 1, 2022 only under the following circumstances: (1) during any calendar quarter commencing after the calendar quarter ending on March 31, 2018 (and only during such calendar quarter), if the last reported sale price of the common stock for at least 20 trading days (whether or not consecutive) during a period of 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price on each applicable trading day; (2) during the five business day period after any ten consecutive trading day period, or the measurement period, in which the trading price (as defined below) per $1,000 principal amount of notes for each trading day of the measurement period was less than 98% of the product of the last reported sale price of our common stock and the conversion rate on each such trading day; (3) if we call any or all of the notes for redemption at any time prior to the close of business on the scheduled trading day immediately preceding the redemption date or (4) upon the occurrence of specified corporate events. On or after May 1, 2022 until the close of business on the second scheduled trading day immediately preceding the maturity date, holders may convert their notes at any time, regardless of the foregoing circumstances. Upon conversion, we will pay or deliver, as the case may be, cash, shares of our common stock or a combination of cash and shares of our common stock, at our election, as described in this prospectus supplement.

The conversion rate will initially be              shares of common stock per $1,000 principal amount of notes (equivalent to an initial conversion price of approximately $             per share of common stock). The conversion rate will be subject to adjustment in some events but will not be adjusted for any accrued and unpaid interest. In addition, following certain corporate events that occur prior to the maturity date or if we deliver a notice of redemption, we will, in certain circumstances, increase the conversion rate for a holder who elects to convert its notes in connection with such a corporate event or notice of redemption, as the case may be.

We may not redeem the notes prior to November 6, 2020. We may redeem for cash all or any portion of the notes, at our option, on or after November 6, 2020 if the last reported sale price of our common stock has been at least 130% of the conversion price then in effect for at least 20 trading days (whether or not consecutive), including the trading day immediately preceding the date on which we provide notice of redemption, during any 30 consecutive trading day period ending on, and including, the trading day immediately preceding the date on which we provide notice of redemption at a redemption price equal to 100% of the principal amount of the notes to be redeemed, plus accrued and unpaid interest to, but excluding, the redemption date. No sinking fund is provided for the notes.

If we undergo a fundamental change, holders may require us to repurchase for cash all or any portion of their notes at a fundamental change repurchase price equal to 100% of the principal amount of the notes to be repurchased, plus accrued and unpaid interest to, but excluding, the fundamental change repurchase date.

The notes will be our senior unsecured obligations and will rank senior in right of payment to any of our indebtedness that is expressly subordinated in right of payment to the notes; equal in right of payment to any of our unsecured indebtedness that is not so subordinated; effectively junior in right of payment to any of our secured indebtedness to the extent of the value of the assets securing such indebtedness; and structurally junior to all indebtedness and other liabilities (including trade payables) of our subsidiaries.

Concurrently with this offering of notes, Jaime Ellertson, our Chief Executive Officer, is offering 650,000 shares of our common stock for resale pursuant to a separate prospectus supplement. The closing of this offering is not conditioned upon the closing of the offering of common stock and the closing of the offering of common stock is not conditioned upon the closing of this offering.

We do not intend to apply to list the notes on any securities exchange or any automated dealer quotation system. Our common stock is listed on The NASDAQ Global Market under the symbol “EVBG.” The last reported sale price of our common stock on The NASDAQ Global Market on November 13, 2017 was $28.68 per share.

We are an “emerging growth company” as defined under the U.S. federal securities laws and have elected to comply with certain reduced public company disclosure and reporting requirements. See “Prospectus Summary—Implications of Being an Emerging Growth Company.”

Investing in the notes involves a high degree of risk. See “Risk Factors” beginning on page S-10 of this prospectus supplement.

We have granted the underwriters the right to purchase, exercisable within a 30-day period, up to an additional $15,000,000 principal amount of notes, solely to cover over-allotments.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of the notes or determined if this prospectus supplement or the accompanying prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

We expect that delivery of the notes will be made to investors in book-entry form through The Depository Trust Company on or about November     , 2017.

Joint Book-Running Managers

Co-Managers

Prospectus Supplement dated November     , 2017

TABLE OF CONTENTS

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ABOUT THIS PROSPECTUS SUPPLEMENT

This prospectus supplement and the accompanying prospectus are part of a registration statement that we filed with the Securities and Exchange Commission, or SEC, using a shelf registration process. Both this prospectus supplement and the accompanying prospectus include or incorporate by reference important information about us, our common stock and other information you should know before investing. You should read both this prospectus supplement and the accompanying prospectus and the documents incorporated herein and therein by reference (see the sections entitled “Incorporation of Certain Information by Reference”), as well as any additional information described under “Where You Can Find More Information” in this prospectus supplement before making an investment decision.

We have not authorized anyone to provide any information other than that contained or incorporated by reference in this prospectus supplement, in the accompanying prospectus or in any free writing prospectus prepared by or on behalf of us or to which we have referred you. We do not take responsibility for, and can provide no assurance as to the reliability of, any other information that others may give you. This prospectus supplement and the accompanying prospectus do not constitute an offer to sell or the solicitation of an offer to buy any securities other than the securities described in this prospectus supplement or an offer to sell or the solicitation of any offer to buy such securities in any circumstances in which such offer or solicitation is unlawful. You should assume that the information appearing in this prospectus supplement and the accompanying prospectus, the documents incorporated by reference and any related free writing prospectus is accurate only as of their respective dates. Our business, financial condition, results of operations and prospects may have changed materially since those dates.

This prospectus supplement may add to, update or change the information in the accompanying prospectus. To the extent there is a conflict between the information contained in this prospectus supplement, on the one hand, and the information contained in the accompanying prospectus or in any document incorporated by reference that was filed with the SEC before the date of this prospectus supplement, on the other hand, you should rely on the information in this prospectus supplement. If any statement in one of these documents is inconsistent with a statement in another document having a later date, for example, a document incorporated by reference in the accompanying prospectus, the statement in the document having the later date modifies or supersedes the earlier statement.

Unless the context otherwise indicates, references in this prospectus to “Everbridge,” “we,” “our,” “us” and “the Company” refer, collectively, to Everbridge, Inc., a Delaware corporation. Our principal executive offices are located at 25 Corporate Drive, Suite 400, Burlington, Massachusetts 01803 and our telephone number is (818) 230-9700.

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RISK FACTORS

Investing in our securities involves a high degree of risk. Before deciding whether to invest in our securities, you should carefully consider the risks described in this prospectus supplement and any related free writing prospectus, as well as other information we include or incorporate by reference into this prospectus supplement, before making an investment decision. Our business, financial condition or results of operations could be materially adversely affected by any of these risks. The trading price of our securities could decline due to the occurrence of any of these risks, and you may lose all or part of your investment. This prospectus and the documents incorporated herein by reference also contain forward-looking statements that involve risks and uncertainties. Actual results could differ materially from those anticipated in these forward-looking statements as a result of certain factors, including the risks described below and in the documents incorporated herein by reference, including in (1) our most recent annual report on Form 10-K on file with the SEC, (2) our most recent quarterly report on Form 10-Q on file with the SEC and (3) as well as any amendments thereto reflected in subsequent filings with the SEC, all of which are incorporated by reference into this prospectus in their entirety, together with other information in this prospectus supplement, the documents incorporated by reference and any free writing prospectus that we may authorize.

Risks Related to the Notes and Our Common Stock

The notes are effectively subordinated to our secured debt and any liabilities of our subsidiaries.

The notes will rank senior in right of payment to any of our indebtedness that is expressly subordinated in right of payment to the notes; equal in right of payment to any of our liabilities that are not so subordinated; effectively junior in right of payment to any of our secured indebtedness, including any indebtedness under our credit facility, to the extent of the value of the assets securing such indebtedness; and structurally junior to all indebtedness and other liabilities (including trade payables) of our subsidiaries. In the event of our bankruptcy, liquidation, reorganization or other winding up, our assets that secure debt ranking senior or equal in right of payment to the notes will be available to pay obligations on the notes only after the secured debt has been repaid in full from these assets. There may not be sufficient assets remaining to pay amounts due on any or all of the notes then outstanding. The indenture governing the notes will not prohibit us from incurring additional senior debt or secured debt, nor does it prohibit any of our subsidiaries from incurring additional liabilities.

As of September 30, 2017, we and our subsidiaries had no consolidated indebtedness and our subsidiaries had $1.8 million of other liabilities (including trade payables, but excluding intercompany obligations and liabilities of a type not required to be reflected on a balance sheet of such subsidiaries in accordance with GAAP) to which the notes would have been structurally subordinated. After giving effect to the issuance of the notes (assuming no exercise of the underwriters’ over-allotment option) and the use of proceeds therefrom, our total consolidated indebtedness would have been $100 million.

Servicing our debt requires a significant amount of cash, and we may not have sufficient cash flow from our business to pay our substantial debt.

Our ability to make scheduled payments of the principal of, to pay interest on or to refinance our indebtedness, including the notes and any future borrowings under our credit facility, depends on our future performance, which is subject to economic, financial, competitive and other factors beyond our control. Our business may not continue to generate cash flow from operations in the future sufficient to service our debt and make necessary capital expenditures. If we are unable to generate such cash flow, we may be required to adopt one or more alternatives, such as selling assets, restructuring debt or obtaining additional equity capital on terms that may be onerous or highly dilutive. Our ability to refinance our indebtedness will depend on the capital markets and our financial condition at such time. We may not be able to engage in any of these activities or engage in these activities on desirable terms, which could result in a default on our debt obligations.

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Recent and future regulatory actions and other events may adversely affect the trading price and liquidity of the notes.

We expect that many investors in, and potential purchasers of, the notes will employ, or seek to employ, a convertible arbitrage strategy with respect to the notes. Investors would typically implement such a strategy by selling short the common stock underlying the notes and dynamically adjusting their short position while continuing to hold the notes. Investors may also implement this type of strategy by entering into swaps on our common stock in lieu of or in addition to short selling the common stock.

The SEC and other regulatory and self-regulatory authorities have implemented various rules and taken certain actions, and may in the future adopt additional rules and take other actions, that may impact those engaging in short selling activity involving equity securities (including our common stock). Such rules and actions include Rule 201 of SEC Regulation SHO, the adoption by the Financial Industry Regulatory Authority, Inc. and the national securities exchanges of a “Limit Up-Limit Down” program, the imposition of market-wide circuit breakers that halt trading of securities for certain periods following specific market declines, and the implementation of certain regulatory reforms required by the Dodd-Frank Wall Street Reform and Consumer Protection Act of 2010. Any governmental or regulatory action that restricts the ability of investors in, or potential purchasers of, the notes to effect short sales of our common stock, borrow our common stock or enter into swaps on our common stock could adversely affect the trading price and the liquidity of the notes.

Volatility in the market price and trading volume of our common stock could adversely impact the trading price of the notes.

The stock market in recent years has experienced significant price and volume fluctuations that have often been unrelated to the operating performance of companies. The market price of our common stock could fluctuate significantly for many reasons, including in response to the risks described in this section, elsewhere in this prospectus supplement or the accompanying prospectus or the documents we have incorporated by reference in this prospectus supplement or the accompanying prospectus, or for reasons unrelated to our operations, such as reports by industry analysts, investor perceptions or negative announcements by our customers, competitors or suppliers regarding their own performance, as well as industry conditions and general financial, economic and political instability. A decrease in the market price of our common stock would likely adversely impact the trading price of the notes. The market price of our common stock could also be affected by possible sales of our common stock by investors who view the notes as a more attractive means of equity participation in us and by hedging or arbitrage trading activity that we expect to develop involving our common stock. This trading activity could, in turn, affect the trading price of the notes.

Despite our consolidated debt levels following issuance of the notes, we may still incur substantially more debt or take other actions which would intensify the risks discussed above.

Despite our consolidated debt levels following issuance of the notes, we and our subsidiaries may be able to incur substantial additional debt in the future, subject to the restrictions contained in our debt instruments, some of which may be secured debt. As of September 30, 2017, no amounts had been drawn under our credit facility, but we may incur up to $15.0 million in secured indebtedness thereunder, subject to the conditions to borrowing therein. We will not be restricted under the terms of the indenture governing the notes from incurring additional debt, securing existing or future debt, recapitalizing our debt or taking a number of other actions that are not limited by the terms of the indenture governing the notes that could have the effect of diminishing our ability to make payments on the notes when due. Our existing credit facility restricts our ability to incur additional indebtedness, including secured indebtedness, but if our credit facility matures or is repaid, we may not be subject to such restrictions under the terms of any subsequent indebtedness.

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We may not have the ability to raise the funds necessary to settle for cash conversions of the notes or to repurchase the notes for cash upon a fundamental change, and our future debt may contain limitations on our ability to pay cash upon conversion or repurchase of the notes.

Holders of the notes will have the right to require us to repurchase their notes upon the occurrence of a fundamental change at a fundamental change repurchase price equal to 100% of the principal amount of the notes to be repurchased, plus accrued and unpaid interest, if any, as described under “Description of Notes—Fundamental Change Permits Holders to Require Us to Repurchase Notes.” In addition, upon conversion of the notes, unless we elect to deliver solely shares of our common stock to settle such conversion (other than paying cash in lieu of delivering any fractional share), we will be required to make cash payments in respect of the notes being converted as described under “Description of Notes—Conversion Rights—Settlement upon Conversion.” However, we may not have enough available cash or be able to obtain financing at the time we are required to make repurchases of notes surrendered therefor or notes being converted.

In addition, our ability to repurchase the notes or to pay cash upon conversions of the notes may be limited by law, by regulatory authority or by agreements governing our indebtedness that exist at the time of the repurchase. Our failure to repurchase notes at a time when the repurchase is required by the indenture or to pay any cash payable on future conversions of the notes as required by the indenture would constitute a default under the indenture. A default under the indenture or the fundamental change itself could also lead to a default under agreements governing our future indebtedness. If the repayment of the related indebtedness were to be accelerated after any applicable notice or grace periods, we may not have sufficient funds to repay the indebtedness and repurchase the notes or make cash payments upon conversions thereof.

Redemption may adversely affect your return on the notes.

We may not redeem the notes prior to November 6, 2020. We may redeem for cash all or any portion of the notes, at our option, on or after November 6, 2020 if the last reported sale price of our common stock has been at least 130% of the conversion price then in effect for at least 20 trading days (whether or not consecutive), including the trading day immediately preceding the date on which we provide notice of redemption, during any 30 consecutive trading day period ending on, and including, the trading day immediately preceding the date on which we provide notice of redemption at a redemption price equal to 100% of the principal amount of the notes to be redeemed, plus accrued and unpaid interest to, but excluding, the redemption date. As a result, we may choose to redeem some or all of the notes, including at times when prevailing interest rates are relatively low. As a result, you may not be able to reinvest the proceeds you receive from the redemption in a comparable security at an effective interest rate as high as the interest rate on your notes being redeemed. See “Description of Notes—Options Redemption On or After November 6, 2020.”

The conditional conversion feature of the notes, if triggered, may adversely affect our financial condition and operating results.

In the event the conditional conversion feature of the notes is triggered, holders of notes will be entitled to convert the notes at any time during specified periods at their option. See “Description of Notes—Conversion Rights.” If one or more holders elect to convert their notes, unless we elect to satisfy our conversion obligation by delivering solely shares of our common stock (other than paying cash in lieu of delivering any fractional share), we would be required to settle a portion or all of our conversion obligation through the payment of cash, which could adversely affect our liquidity. In addition, even if holders do not elect to convert their notes, we could be required under applicable accounting rules to reclassify all or a portion of the outstanding principal of the notes as a current rather than long-term liability, which would result in a material reduction of our net working capital.

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The accounting method for convertible debt securities that may be settled in cash, such as the notes, could have a material effect on our reported financial results.

In May 2008, the Financial Accounting Standards Board, which we refer to as FASB, issued FASB Staff Position No. APB 14-1, Accounting for Convertible Debt Instruments That May Be Settled in Cash Upon Conversion (Including Partial Cash Settlement), which has subsequently been codified as Accounting Standards Codification 470-20, Debt with Conversion and Other Options, which we refer to as ASC 470-20. Under ASC 470-20, an entity must separately account for the liability and equity components of the convertible debt instruments (such as the notes) that may be settled entirely or partially in cash upon conversion in a manner that reflects the issuer’s economic interest cost. The effect of ASC 470-20 on the accounting for the notes is that the equity component is required to be included in the additional paid-in capital section of stockholders’ equity on our consolidated balance sheet, and the value of the equity component would be treated as original issue discount for purposes of accounting for the debt component of the notes. As a result, we will be required to record a greater amount of non-cash interest expense in current periods presented as a result of the amortization of the discounted carrying value of the notes to their face amount over the term of the notes. We will report lower net income in our financial results because ASC 470-20 will require interest to include both the current period’s amortization of the debt discount and the instrument’s coupon interest, which could adversely affect our reported or future financial results, the trading price of our common stock and the trading price of the notes.

In addition, under certain circumstances, convertible debt instruments (such as the notes) that may be settled entirely or partly in cash are currently accounted for utilizing the treasury stock method, the effect of which is that the shares issuable upon conversion of the notes are not included in the calculation of diluted earnings per share except to the extent that the conversion value of the notes exceeds their principal amount. Under the treasury stock method, for diluted earnings per share purposes, the transaction is accounted for as if the number of shares of common stock that would be necessary to settle such excess, if we elected to settle such excess in shares, are issued. We cannot be sure that the accounting standards in the future will continue to permit the use of the treasury stock method. If we are unable to use the treasury stock method in accounting for the shares issuable upon conversion of the notes, then our diluted earnings per share would be adversely affected.

The Concurrent Offering, and future sales of our common stock or equity-linked securities in the public market, could lower the market price for our common stock and adversely impact the trading price of the notes.

Concurrently with this offering of notes, Jaime Ellertson, our Chief Executive Officer, is offering 650,000 shares of our common stock for resale, which we refer to as the Concurrent Offering. In the Concurrent Offering, Mr. Ellertson has granted the underwriters of that offering an option to purchase an additional 97,500 shares of our common stock. We will not receive any of the proceeds from the shares of common stock sold by Mr. Ellertson. The Concurrent Offering is being conducted as a separate public offering by means of a separate prospectus supplement. The offering of the notes pursuant to this prospectus supplement is not contingent upon the completion of the Concurrent Offering and the Concurrent Offering is not contingent upon the completion of the offering of the notes. We cannot assure you that either or both of the offerings will be completed. The sale of our common stock in the Concurrent Offering could lower the market price for our common stock and adversely impact the trading price of the notes.

In the future, we may sell additional shares of our common stock or equity-linked securities to raise capital. In addition, a substantial number of shares of our common stock are reserved for issuance upon the exercise of stock options, settlement of other equity incentive awards, and conversion of the notes. We cannot predict the size of future issuances or the effect, if any, that they may have on the market price for our common stock. The issuance and sale of substantial amounts of common stock or equity-linked securities, or the perception that such issuances and sales may occur, could adversely affect the trading price of the notes and the market price of our common stock and impair our ability to raise capital through the sale of additional equity or equity-linked securities.

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Holders of notes will not be entitled to any rights with respect to our common stock, but they will be subject to all changes made with respect to them to the extent our conversion obligation includes shares of our common stock.

Holders of notes will not be entitled to any rights with respect to our common stock (including, without limitation, voting rights and rights to receive any dividends or other distributions on our common stock) prior to the conversion date relating to such notes (if we have elected to settle the relevant conversion by delivering solely shares of our common stock (other than paying cash in lieu of delivering any fractional share)) or the last trading day of the relevant observation period (if we elect to pay and deliver, as the case may be, a combination of cash and shares of our common stock in respect of the relevant conversion), but holders of notes will be subject to all changes affecting our common stock. For example, if an amendment is proposed to our certificate of incorporation or bylaws requiring stockholder approval and the record date for determining the stockholders of record entitled to vote on the amendment occurs prior to the conversion date related to a holder’s conversion of its notes (if we have elected to settle the relevant conversion by delivering solely shares of our common stock (other than paying cash in lieu of delivering any fractional share)) or the last trading day of the relevant observation period (if we elect to pay and deliver, as the case may be, a combination of cash and shares of our common stock in respect of the relevant conversion), such holder will not be entitled to vote on the amendment, although such holder will nevertheless be subject to any changes affecting our common stock.

The conditional conversion feature of the notes could result in your receiving less than the value of our common stock into which the notes would otherwise be convertible.

Prior to the close of business on the business day immediately preceding May 1, 2022, you may convert your notes only if specified conditions are met. If the specific conditions for conversion are not met, you will not be able to convert your notes, and you may not be able to receive the value of the cash, common stock or a combination of cash and common stock, as applicable, into which the notes would otherwise be convertible.

Upon conversion of the notes, you may receive less valuable consideration than expected because the value of our common stock may decline after you exercise your conversion right but before we settle our conversion obligation.

Under the notes, a converting holder will be exposed to fluctuations in the value of our common stock during the period from the date such holder surrenders notes for conversion until the date we settle our conversion obligation.

Upon conversion of the notes, we have the option to pay or deliver, as the case may be, cash, shares of our common stock, or a combination of cash and shares of our common stock. If we elect to satisfy our conversion obligation in cash or a combination of cash and shares of our common stock, the amount of consideration that you will receive upon conversion of your notes will be determined by reference to the volume-weighted average price of our common stock for each trading day in a 40 trading day observation period. As described under “Description of Notes—Conversion Rights—Settlement upon Conversion,” this period would be (i) subject to clause (ii), if the relevant conversion date occurs prior to May 1, 2022, the 40 consecutive trading day period beginning on, and including, the second trading day immediately succeeding such conversion date; (ii) if the relevant conversion date occurs on or after the date of our issuance of a notice of redemption with respect to the notes as described under “Description of Notes—Optional Redemption On or After November 6, 2020” and prior to the relevant redemption date, the 40 consecutive trading days beginning on, and including, the 41st scheduled trading day immediately preceding such redemption date; and (iii) subject to clause (ii), if the relevant conversion date occurs on or after May 1, 2022, the 40 consecutive trading days beginning on, and including, the 41st scheduled trading day immediately preceding the maturity date. Accordingly, if the price of our common stock decreases during this period, the amount and/or value of consideration you receive will be adversely affected. In addition, if the market price of our common stock at the end of such period is below the average volume-weighted average price of our common stock during such period, the value of any shares of our common

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stock that you will receive in satisfaction of our conversion obligation will be less than the value used to determine the number of shares that you will receive.

If we elect to satisfy our conversion obligation solely in shares of our common stock upon conversion of the notes, we will be required to deliver the shares of our common stock, together with cash for any fractional share, on the second business day following the relevant conversion date. Accordingly, if the price of our common stock decreases during this period, the value of the shares that you receive will be adversely affected and would be less than the conversion value of the notes on the conversion date.

The notes are not protected by restrictive covenants.

The indenture governing the notes will not contain any financial or operating covenants or restrictions on the payments of dividends, the incurrence of indebtedness or the issuance or repurchase of securities by us or any of our subsidiaries. The indenture will not contain any covenants or other provisions to afford protection to holders of the notes in the event of a fundamental change or other corporate transaction involving us except to the extent described under “Description of Notes—Fundamental Change Permits Holders to Require Us to Repurchase Notes,” “Description of Notes—Conversion Rights—Increase in Conversion Rate upon Conversion upon a Make-whole Fundamental Change or Notice of Redemption” and “Description of Notes—Consolidation, Merger and Sale of Assets.”

The increase in the conversion rate for notes converted in connection with a make-whole fundamental change or redemption may not adequately compensate you for any lost value of your notes as a result of such transaction.

If a make-whole fundamental change or redemption occurs prior to the maturity date, under certain circumstances, we will increase the conversion rate by a number of additional shares of our common stock for notes converted in connection with such make-whole fundamental change or redemption, as applicable. The increase in the conversion rate will be determined based on the date on which the specified corporate transaction becomes effective or the date of the redemption notice, as the case may be, and the price paid (or deemed to be paid) per share of our common stock in such transaction, as described below under “Description of Notes—Conversion Rights—Increase in Conversion Rate upon Conversion upon a Make-whole Fundamental Change or Notice of Redemption.” The increase in the conversion rate for notes converted in connection with a make-whole fundamental change or redemption, as applicable, may not adequately compensate you for any lost value of your notes as a result of such transaction or in connection with the relevant redemption, as applicable. In addition, if the price paid (or deemed paid) per share of our common stock in the transaction or in connection with the relevant redemption, as applicable, is greater than $                 per share or less than $                 per share (in each case, subject to adjustment), no additional shares will be added to the conversion rate. Moreover, in no event will the conversion rate per $1,000 principal amount of notes as a result of this adjustment exceed                 shares of common stock, subject to adjustment in the same manner as the conversion rate as set forth under “Description of Notes—Conversion Rights—Conversion Rate Adjustments.”

Our obligation to increase the conversion rate for notes converted in connection with a make-whole fundamental change or redemption could be considered a penalty, in which case the enforceability thereof would be subject to general principles of reasonableness and equitable remedies.

Upon any redemption of the notes on or after November 6, 2020 or any conversion of the notes in connection with a redemption notice, the cash comprising the redemption price, in the case of a redemption, or the applicable conversion rate, in the case of a conversion in connection with a redemption notice, as applicable, may not fully compensate you for future interest payments or lost time value of your notes.

On or after November 6, 2020, we may redeem for cash all or any portion of the notes, at our option, if the last reported sale price of our common stock has been at least 130% of the conversion price then in effect for at

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least 20 trading days (whether or not consecutive), including the trading day immediately preceding the date on which we provide notice of redemption, during any 30 consecutive trading day period ending on, and including, the trading day immediately preceding the date on which we provide notice of redemption at a redemption price equal to 100% of the principal amount of the notes to be redeemed, plus accrued and unpaid interest to, but excluding, the redemption date. If we call any or all of the notes for redemption, you may convert your notes at any time prior to the close of business on the scheduled trading day immediately preceding the redemption date. Upon such redemption or conversion, the cash comprising the redemption price, in the case of a redemption, or the applicable conversion rate, in the case of a conversion in connection with a redemption notice, in either case, may not fully compensate you for any future interest payments that you would have otherwise received or any other lost time value of your notes. See “Description of Notes—Optional Redemption On or After November 6, 2020.”

The conversion rate of the notes may not be adjusted for all dilutive events.

The conversion rate of the notes is subject to adjustment for certain events, including, but not limited to, the issuance of certain stock dividends on our common stock, the issuance of certain rights or warrants, subdivisions, combinations, distributions of capital stock, indebtedness, or assets, cash dividends and certain issuer tender or exchange offers as described under “Description of Notes—Conversion Rights—Conversion Rate Adjustments.” However, the conversion rate will not be adjusted for other events, such as a third-party tender or exchange offer or an issuance of common stock for cash, that may adversely affect the trading price of the notes or our common stock. An event that adversely affects the value of the notes may occur, and that event may not result in an adjustment to the conversion rate.

Some significant restructuring transactions may not constitute a fundamental change, in which case we would not be obligated to offer to repurchase the notes.

Upon the occurrence of a fundamental change, you have the right to require us to repurchase your notes. However, the fundamental change provisions will not afford protection to holders of notes in the event of other transactions that could adversely affect the notes. For example, transactions such as leveraged recapitalizations, refinancings, restructurings or acquisitions initiated by us may not constitute a fundamental change requiring us to repurchase the notes. In the event of any such transaction, the holders would not have the right to require us to repurchase the notes, even though each of these transactions could increase the amount of our indebtedness, or otherwise adversely affect our capital structure or any credit ratings, thereby adversely affecting the holders of notes.

We cannot assure you that an active trading market will develop for the notes.

Prior to this offering, there has been no trading market for the notes, and we do not intend to apply to list the notes on any securities exchange or to arrange for quotation on any automated dealer quotation system. We have been informed by the underwriters that they intend to make a market in the notes after the offering is completed. However, the underwriters may cease their market-making at any time without notice. In addition, the liquidity of the trading market in the notes, and the market price quoted for the notes, may be adversely affected by changes in the overall market for this type of security and by changes in our financial performance or prospects or in the prospects for companies in our industry generally. As a result, we cannot assure you that an active trading market will develop for the notes. If an active trading market does not develop or is not maintained, the market price and liquidity of the notes may be adversely affected. In that case you may not be able to sell your notes at a particular time or you may not be able to sell your notes at a favorable price.

Any adverse rating of the notes may cause their trading price to fall.

We do not intend to seek a rating on the notes. However, if a rating service were to rate the notes and if such rating service were to lower its rating on the notes below the rating initially assigned to the notes or otherwise announces its intention to put the notes on credit watch, the trading price of the notes could decline.

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You may be subject to tax if we make or fail to make certain adjustments to the conversion rate of the notes even though you do not receive a corresponding cash distribution.

The conversion rate of the notes is subject to adjustment in certain circumstances, including the payment of cash dividends. If the conversion rate is adjusted as a result of a cash dividend paid to our common stockholders, you may be deemed to have received a dividend subject to U.S. federal income tax without the receipt of any cash. In addition, a failure to adjust (or to adjust adequately) the conversion rate after an event that increases your proportionate interest in us could be treated as a deemed taxable dividend to you. If a make-whole fundamental change occurs prior to the maturity date, under some circumstances, we will increase the conversion rate for notes converted in connection with the make-whole fundamental change or redemption, as the case may be. Such increase may also be treated as a distribution subject to U.S. federal income tax as a dividend. See “Certain Material U.S. Federal Income Tax Considerations.” If you are a non-U.S. holder (as defined in “Certain Material U.S. Federal Income Tax Considerations”), any deemed dividend would be subject to U.S. federal withholding tax at a 30% rate, or such lower rate as may be specified by an applicable treaty, and if you are a U.S. holder (as defined in “Certain Material U.S. Federal Income Tax Considerations”), any deemed dividend may be subject to U.S. federal backup withholding tax at a 28% rate, which, in each case, may be withheld from subsequent payments on the notes or other amounts received by you. See “Certain Material U.S. Federal Income Tax Considerations.”

The capped call transactions may affect the value of the notes and our common stock.

In connection with the pricing of the notes, we expect to enter into capped call transactions with the option counterparties. The capped call transactions are expected generally to reduce the potential dilution upon conversion of the notes and/or offset any cash payments we are required to make in excess of the principal amount of converted notes, as the case may be, with such reduction and/or offset subject to a cap. If the underwriters exercise their over-allotment option, we expect to enter into additional capped call transactions with the option counterparties.

In connection with establishing their initial hedges of the capped call transactions, the option counterparties or their respective affiliates expect to enter into various derivative transactions with respect to our common stock concurrently with or shortly after the pricing of the notes. This activity could increase (or reduce the size of any decrease in) the market price of our common stock or the notes at that time.

In addition, the option counterparties or their respective affiliates may modify their hedge positions by entering into or unwinding derivatives with respect to our common stock and/or purchasing or selling our common stock or other securities of ours in secondary market transactions following the pricing of the notes and prior to the maturity of the notes (and are likely to do so during any observation period related to a conversion of notes). This activity could also cause or avoid an increase or a decrease in the market price of our common stock or the notes, which could affect your ability to convert the notes and, to the extent the activity occurs during any observation period related to a conversion of notes, it could affect the number of shares and value of the consideration that you will receive upon conversion of the notes.

In addition, if any such capped call transactions fail to become effective, whether or not this offering of notes is completed, the option counterparties or their respective affiliates may unwind their hedge positions with respect to our common stock, which could adversely affect the value of our common stock and, if the notes have been issued, the value of the notes.

We may invest or spend the proceeds of this offering in ways with which you may not agree or in ways which may not yield a return.

We anticipate that the net proceeds from this offering will be used for general corporate purposes, including working capital. We may also use a portion of the proceeds from this offering for acquisitions or strategic

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investments in complementary businesses or technologies or for geographic expansion, although we do not currently have any plans for any such acquisitions, investments or expansion. Our management will have considerable discretion in the application of the net proceeds, and you will not have the opportunity to assess whether the proceeds are being used appropriately. The net proceeds may be invested with a view towards long-term benefits for our stockholders and this may not increase our operating results or market value. The failure by our management to apply these funds effectively may adversely affect the return on your investment.

Because the notes will initially be held in book-entry form, holders must rely on DTC’s procedures to receive communications relating to the notes and exercise their rights and remedies.

We will initially issue the notes in the form of one or more global notes registered in the name of Cede & Co., as nominee of DTC. Beneficial interests in global notes will be shown on, and transfers of global notes will be effected only through, the records maintained by DTC. Except in limited circumstances, we will not issue certificated notes. See “Description of Notes—Book-Entry, Settlement and Clearance.” Accordingly, if you own a beneficial interest in a global note, then you will not be considered an owner or holder of the notes. Instead, DTC or its nominee will be the sole holder of the notes. Unlike persons who have certificated notes registered in their names, owners of beneficial interests in global notes will not have the direct right to act on our solicitations for consents or requests for waivers or other actions from holders. Instead, those beneficial owners will be permitted to act only to the extent that they have received appropriate proxies to do so from DTC or, if applicable, a DTC participant. The applicable procedures for the granting of these proxies may not be sufficient to enable owners of beneficial interests in global notes to vote on any requested actions on a timely basis. In addition, notices and other communications relating to the notes (including any notice of redemption) will be sent to DTC. We expect DTC to forward any such communications to DTC participants, which in turn would forward such communications to indirect DTC participants. But we can make no assurances that you timely receive any such communications.

The price of our common stock historically has been volatile. This volatility may affect the price at which you could sell the common stock you receive upon conversion of your notes, if any, and the sale of substantial amounts of our common stock could adversely affect the price of our common stock and the value of your notes.

The market price for our common stock has varied between a high of $29.64 on November 7, 2017 and a low of $14.26 on November 30, 2016 in the twelve-month period ending on November 13, 2017. This volatility may affect the price at which you could sell the common stock, if any, you receive upon conversion of your notes, and the sale of substantial amounts of our common stock could adversely affect the price of our common stock and the value of your notes. Our stock price is likely to continue to be volatile and subject to significant price and volume fluctuations in response to market and other factors, including variations in our quarterly operating results from our expectations or those of securities analysts or investors; downward revisions in securities analysts’ estimates; announcement by us or our competitors of significant acquisitions, strategic partnerships, joint ventures or capital commitments; and the other factors discussed elsewhere in this prospectus supplement or the accompanying prospectus or the documents we have incorporated by reference in this prospectus supplement or the accompanying prospectus, or for reasons unrelated to our operations, such as reports by industry analysts, investor perceptions or negative announcements by our customers, competitors or suppliers regarding their own performance, as well as industry conditions and general financial, economic and political instability.

In addition, the sale of substantial amounts of our common stock could adversely impact its price. In addition, as of September 30, 2017, we had outstanding 28,293,369 shares of our common stock, options to purchase 2,469,553 shares of our common stock (of which 768,956 were exercisable as of that date) and 572,000 restricted stock units (none of which were exercisable as of that date). We had also reserved 571,214 shares of common stock for issuance pursuant to our 2016 Employee Stock Purchase Plan. The sale or the availability for sale of a large number of shares of our common stock in the public market could cause the price of our common stock, and the value of your notes, to decline.

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Anti-takeover provisions in our charter documents, under Delaware law and under the indenture may make an acquisition of us, which may be beneficial to our stockholders, more difficult.

Provisions in our certificate of incorporation and bylaws may have the effect of delaying or preventing a change in control or changes in our management. Our certificate of incorporation and bylaws include provisions that:

These provisions may frustrate or prevent any attempts by our stockholders to replace or remove our current management by making it more difficult for stockholders to replace members of our board of directors, which is responsible for appointing the members of our management. In addition, because we are incorporated in Delaware, we are governed by the provisions of Section 203 of the General Corporation Law of the State of Delaware, which generally prohibits a Delaware corporation from engaging in any of a broad range of business combinations with any “interested” stockholder for a period of three years following the date on which the stockholder became an “interested” stockholder. Any of the foregoing provisions could limit the price that investors might be willing to pay in the future for shares of our common stock or the notes, and they could deter potential acquirers of our company, thereby reducing the likelihood that holders of common stock would receive a premium for such common stock in an acquisition.

Furthermore, certain provisions in the notes and the indenture could make a third party attempt to acquire us more difficult or expensive. For example, if a takeover constitutes a fundamental change, then noteholders will have the right to require us to repurchase their notes for cash. In addition, if a takeover constitutes a make-whole fundamental change, then we may be required to temporarily increase the conversion rate. In either case, and in other cases, our obligations under the notes and the indenture could increase the cost of acquiring us or otherwise discourage a third party from acquiring us or removing incumbent management, including in a transaction that noteholders or holders of our common shares may view as favorable.

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SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

This prospectus supplement, the accompanying prospectus, the documents incorporated by reference and any free writing prospectus prepared by or on behalf of us or the selling stockholder or to which we or the selling stockholder have referred you contain “forward-looking statements” within the meaning of Section 27A of the Securities Act of 1933, as amended, or the Securities Act, and Section 21E of the Securities Exchange Act of 1934, as amended, or the Exchange Act. Any statements about our expectations, beliefs, plans, objectives, assumptions or future events or performance are not historical facts and may be forward-looking. These statements are often, but are not always, made through the use of words or phrases such as “may,” “could,” “should,” “expects,” “intends,” “plans,” “anticipates,” “believes,” “estimates,” “predicts,” “projects,” “potential,” “continue,” and similar expressions, or the negative of these terms, or similar expressions. Accordingly, these statements involve estimates, assumptions and uncertainties which could cause actual results to differ materially from those expressed in them. Given these risks and uncertainties, you should not place undue reliance on these forward-looking statements. We discuss many of these risks and uncertainties in greater detail in the risk factors incorporated by reference herein under the heading section captioned “Risk Factors” in this prospectus supplement.

Forward-looking statements are based on our management’s belief and assumptions and on information currently available to our management. These statements relate to future events or our future financial performance, and involve known and unknown risks, uncertainties and other factors that may cause our actual results, levels of activity, performance or achievements to be materially different from any future results, levels of activity, performance or achievements expressed or implied by these forward-looking statements.

Except as required by law, we assume no obligation to update these forward-looking statements, or to update the reasons actual results could differ materially from those anticipated in these forward-looking statements, even if new information becomes available in the future.

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RATIO OF EARNINGS TO FIXED CHARGES

The following table sets forth our ratio of earnings to fixed charges for each of the periods presented. Our net losses were insufficient to cover fixed charges for each of the periods presented. Because of these deficiencies, the ratio information is not applicable for those periods. The extent to which earnings were insufficient to cover fixed charges for those periods is shown below. Amounts are shown in thousands, except for ratios.

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USE OF PROCEEDS

We estimate that the net proceeds from our issuance and sale of the notes in this offering will be approximately $96.9 million, (or, if the underwriters fully exercise their option to purchase additional notes, $111.5 million), after deducting the underwriting discounts and commissions and estimated offering expenses that are payable by us. We will not receive any of the proceeds from the sale of shares by the selling stockholders in the Concurrent Offering. We will, however, bear the costs associated with the sale of shares by the selling stockholder, other than underwriting discounts and commissions.

We intend to use approximately $             million of the net proceeds from this offering to pay the cost of the capped call transactions. We intend to use the remainder of the net proceeds from this offering for working capital and other general corporate purposes, including investments in sales and marketing in the United States and internationally and in research and development. We may also use a portion of the proceeds from this offering for acquisitions or strategic investments in complementary businesses or technologies or for geographic expansion, although we do not currently have any plans for any such acquisitions, or investments or expansion. We have not allocated specific amounts of net proceeds for any of these purposes.

If the underwriters exercise their over-allotment option, we may use a portion of the net proceeds from the sale of the additional notes to enter into additional capped call transactions with the option counterparties and for working capital and other general corporate purposes.

The expected use of net proceeds from this offering represents our intentions based upon our present plans and business conditions. We cannot predict with certainty all of the particular uses for the proceeds of this offering or the amounts that we will actually spend on the uses set forth above. Accordingly, our management will have significant flexibility in applying the net proceeds of this offering. The timing and amount of our actual expenditures will be based on many factors, including cash flows from operations and the anticipated growth of our business. Pending their use, we intend to invest the net proceeds of this offering in a variety of capital-preservation investments, including short- and intermediate-term, interest-bearing, investment-grade securities.

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DIVIDEND POLICY

We have never declared or paid any dividends on our capital stock. We currently intend to retain all available funds and any future earnings for the operation and expansion of our business and, therefore, we do not anticipate declaring or paying cash dividends in the foreseeable future. The payment of dividends will be at the discretion of our board of directors and will depend on our results of operations, capital requirements, financial condition, prospects, contractual arrangements, any limitations on payment of dividends present in our current and future debt agreements, and other factors that our board of directors may deem relevant. We are subject to several covenants under our credit facility that place restrictions on our ability to pay dividends.

CONCURRENT OFFERING OF COMMON STOCK

Concurrently with this offering of notes, Jaime Ellertson, our Chief Executive Officer, is offering 650,000 shares of our common stock for resale, which we refer to as the Concurrent Offering. In the Concurrent Offering, Mr. Ellertson has granted the underwriters of that offering an option to purchase an additional 97,500 shares of our common stock. We will not receive any of the proceeds from the shares of common stock sold by Mr. Ellertson. The Concurrent Offering is being conducted as a separate public offering by means of a separate prospectus supplement. The offering of the notes pursuant to this prospectus supplement is not contingent upon the completion of the Concurrent Offering and the Concurrent Offering is not contingent upon the completion of the offering of the notes. We cannot assure you that either or both of the offerings will be completed.

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CAPITALIZATION

The following table sets forth our cash and cash equivalents and our capitalization as of September 30, 2017:

The number of shares of our common stock shown as issued and outstanding on an as adjusted basis in the table above is based on 28,293,369 shares of common stock outstanding as of September 30, 2017, and excludes:

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PRICE RANGE OF COMMON STOCK

Our common stock has been listed on The NASDAQ Global Market under the symbol “EVBG” since September 16, 2016. Prior to that date, there was no public trading market for our common stock. Our initial public offering was priced at $12.00 per share on September 15, 2016. The following table sets forth for the periods indicated the high and low sales prices per share of our common stock as reported on The NASDAQ Global Market:

On November 13, 2017, the closing price of our common stock as reported on The NASDAQ Global Market was $28.68 per share. As of such date, we had approximately 500 holders of record of our common stock. The actual number of stockholders is greater than this number of record holders, and includes stockholders who are beneficial owners, but whose shares are held in street name by brokers and other nominees. This number of holders of record also does not include stockholders whose shares may be held in trust by other entities.

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DESCRIPTION OF EXISTING CREDIT FACILITY

In June 2015, we entered into a loan and security agreement by and among Western Alliance Bank (formerly known as Bridge Bank), as lender, us, as a borrower, and our wholly-owned subsidiary IDV Solutions, LLC, as a borrower (together with us, the “borrowers”) (as amended, our “credit facility”). Our credit facility provides for a $15.0 million revolving line of credit that matures on June 30, 2018 and that may be prepaid without penalty. Amounts outstanding under the credit facility bear interest at the prime rate plus 0.75% with accrued interest payable on a monthly basis and outstanding and unpaid principal due upon maturity of the credit facility in June 2018.

Our obligations under our credit facility are secured, subject to customary permitted liens and other agreed upon exceptions, by substantially all of our assets, excluding our intellectual property. Our credit facility contains customary representations and warranties and customary affirmative and negative covenants applicable to us and our subsidiaries, including, among other things, restrictions on indebtedness, liens, investments, mergers, dispositions, prepayment of subordinated indebtedness, and dividends and other distributions, in each case subject to specified exceptions. Our credit facility also contains customary indemnification obligations. Our credit facility further contains a financial covenant that requires us to maintain a monthly recurring revenue rate, measured on a quarterly basis. In addition, our credit facility limits the amount of capital expenditures that we may make in any fiscal year. As of June 30, 2017, we and certain of our subsidiaries that serve as guarantors were in compliance with all covenants.

Events of default under our credit facility include, among others: the borrowers’ failure to timely make payments due under our credit facility; material misrepresentations or misstatements in any representation or warranty of the borrowers; failure by the borrowers to comply with the covenants under the loan and security agreement governing our credit facility; certain defaults under of the documentation governing other indebtedness of the borrowers above a certain amount; insolvency or bankruptcy-related events with respect to the borrowers; and certain judgments against the borrowers; and certain guarantees under our credit facility cease to be in full force and effect.

As of September 30, 2017 and November 13, 2017, there were no outstanding borrowings under our credit facility and the total amount available to be borrowed by us was the lesser of the borrowing base and $15.0 million.

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DESCRIPTION OF NOTES

We will issue the notes under a base indenture dated as of November      , 2017 between us and U.S. Bank National Association, as supplemented by a supplemental indenture with respect to the notes. In this section, we refer to the base indenture (the “base indenture”), as supplemented by the supplemental indenture (the “supplemental indenture”), collectively as the “indenture.” This description of the notes supplements and, to the extent it is inconsistent, replaces the description of the general provisions of the notes and the base indenture in the accompanying prospectus. The terms of the notes include those expressly set forth in the indenture and those made part of the indenture by reference to the Trust Indenture Act of 1939, as amended (the “Trust Indenture Act”).

You may request a copy of the indenture from us as described under “Where You Can Find More Information.”

The following description is a summary of the material provisions of the notes and the indenture and does not purport to be complete. This summary is subject to and is qualified by reference to all the provisions of the notes and the indenture, including the definitions of certain terms used in the indenture. We urge you to read these documents because they, and not this description, define your rights as a holder of the notes.

For purposes of this description, references to “we,” “our” and “us” refer only to Everbridge, Inc. and not to its subsidiaries.

General

The notes will:

Subject to satisfaction of certain conditions and during the periods described below, the notes may be converted at an initial conversion rate of             shares of common stock per $1,000 principal amount of notes

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(equivalent to an initial conversion price of approximately $             per share of common stock). The conversion rate is subject to adjustment if certain events occur.

We will settle conversions of notes by paying or delivering, as the case may be, cash, shares of our common stock or a combination of cash and shares of our common stock, at our election, as described under “—Conversion Rights—Settlement upon Conversion.” You will not receive any separate cash payment for interest, if any, accrued and unpaid to the conversion date except under the limited circumstances described below.

The indenture will not limit the amount of debt that may be issued by us or our subsidiaries under the indenture or otherwise. The indenture will not contain any financial covenants and will not restrict us from paying dividends or issuing or repurchasing our other securities. Other than restrictions described under “—Fundamental Change Permits Holders to Require Us to Repurchase Notes” and “—Consolidation, Merger and Sale of Assets” below and except for the provisions set forth under “—Conversion Rights—Increase in Conversion Rate upon Conversion upon a Make-whole Fundamental Change or Notice of Redemption,” the indenture will not contain any covenants or other provisions designed to afford holders of the notes protection in the event of a highly leveraged transaction involving us or in the event of a decline in our credit rating as the result of a takeover, recapitalization, highly leveraged transaction or similar restructuring involving us that could adversely affect such holders.

We may, without the consent of, or notice to, the holders, reopen the indenture for the notes and issue additional notes under the indenture with the same terms as the notes offered hereby (other than differences in the issue date, the issue price and interest accrued prior to the issue date of such additional notes and, if applicable, restrictions on transfer in respect of such additional notes) in an unlimited aggregate principal amount; provided that if any such additional notes are not fungible with the notes initially offered hereby for U.S. federal income tax or securities law purposes, such additional notes will have one or more separate CUSIP numbers.

We do not intend to list the notes on any securities exchange or any automated dealer quotation system.

Except to the extent the context otherwise requires, we use the term “notes” in this prospectus supplement to refer to each $1,000 principal amount of notes. We use the term “common stock” in this prospectus supplement to refer to our common stock, par value $0.001 per share. References in this prospectus supplement to a “holder” or “holders” of notes that are held through The Depository Trust Company (“DTC”) are references to owners of beneficial interests in such notes, unless the context otherwise requires. However, we and the trustee will treat the person in whose name the notes are registered (Cede & Co., in the case of notes held through DTC) as the owner of such notes for all purposes. References herein to the “close of business” refer to 5:00 p.m., New York City time, and to the “open of business” refer to 9:00 a.m., New York City time.

Purchase and Cancellation

We will cause all notes surrendered for payment, repurchase (including as described immediately below and in “—Fundamental Change Permits Holders to Require Us to Repurchase Notes”), redemption, registration of transfer or exchange or conversion, if surrendered to us or any of our agents, subsidiaries or affiliates, to be delivered to the trustee for cancellation. All notes delivered to the trustee shall be cancelled promptly by the trustee. Except for notes surrendered for registration of transfer or exchange, no notes shall be authenticated in exchange for any notes cancelled as provided in the indenture.

We may, to the extent permitted by law, and directly or indirectly (regardless of whether such notes are surrendered to us), repurchase notes in the open market or otherwise, whether by us or our subsidiaries or through a private or public tender or exchange offer or through counterparties to private agreements, including by cash-settled swaps or other derivatives, in each case, without prior notice to the holders of the notes. We will cause any notes so repurchased (other than notes repurchased pursuant to cash-settled swaps or other derivatives)

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to be surrendered to the trustee for cancellation, and they will no longer be considered “outstanding” under the indenture upon their repurchase.

Payments on the Notes; Paying Agent and Registrar; Transfer and Exchange

We will pay or cause the paying agent to pay the principal of, and interest on, notes in global form registered in the name of or held by DTC or its nominee by wire transfer in immediately available funds to DTC or its nominee, as the case may be, as the registered holder of such global note.

We will pay or cause the paying agent to pay the principal of any certificated notes at the office or agency designated by us for that purpose. We have initially designated the trustee as our paying agent and registrar and its agency in New York, New York as a place where notes may be presented for payment or for registration of transfer. We may, however, change the paying agent or registrar without prior notice to the holders of the notes, and we may act as paying agent or registrar. Interest on certificated notes will be payable (i) to holders having an aggregate principal amount of $5,000,000 or less, by check mailed to the holders of these notes and (ii) to holders having an aggregate principal amount of more than $5,000,000, either by check mailed to each holder or, upon application by such a holder to the registrar not later than the relevant regular record date, by wire transfer in immediately available funds to that holder’s account within the United States if such holder has provided us, the trustee or the paying agent with the requisite information necessary to make such wire transfer, which application shall remain in effect until the holder notifies, in writing, the registrar to the contrary.

A holder of notes may transfer or exchange notes at the office of the registrar in accordance with the indenture. The registrar and the trustee may require a holder, among other things, to furnish appropriate endorsements and transfer documents. No service charge will be imposed by us, the trustee or the registrar for any registration of transfer or exchange of notes, but we may require a holder to pay a sum sufficient to cover any transfer tax or other similar governmental charge required by law or permitted by the indenture. We are not required to transfer or exchange any note selected for redemption or surrendered for conversion or required repurchase.

The registered holder of a note will be treated as its owner for all purposes.

Interest

The notes will bear cash interest at a rate of     % per year until maturity. Interest on the notes will accrue from November     , 2017 or from the most recent date on which interest has been paid or duly provided for. Interest will be payable semiannually in arrears on May 1 and November 1 of each year, beginning on May 1, 2018.

Interest will be paid to the person in whose name a note is registered at the close of business on April 15 or October 15 (whether or not a business day), as the case may be, immediately preceding the relevant interest payment date (each, a “regular record date”). Interest on the notes will be computed on the basis of a 360-day year composed of twelve 30-day months and, for partial months, on the basis of the number of days actually elapsed in a 30-day month.

If any interest payment date, the maturity date, any redemption date or any earlier required repurchase date upon a fundamental change of a note falls on a day that is not a business day, the required payment will be made on the next succeeding business day with the same force and effect as if made on such scheduled payment date, and no interest on such payment will accrue in respect of the delay. The term “business day” means, with respect to any note, any day other than a Saturday, a Sunday or a day on which the Federal Reserve Bank of New York is authorized or required by law or executive order to close or be closed.

Unless the context otherwise requires, all references to interest in this prospectus supplement include additional interest, if any, payable at our election as the sole remedy relating to the failure to comply with our reporting obligations as described under “—Events of Default.”

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Ranking

The notes will be our general unsecured obligations that rank senior in right of payment to all of our indebtedness that is expressly subordinated in right of payment to the notes. The notes will rank equal in right of payment with all of our liabilities that are not so subordinated. The notes will effectively rank junior to any of our secured indebtedness, including any indebtedness under our credit facility, to the extent of the value of the assets securing such indebtedness. In the event of our bankruptcy, liquidation, reorganization or other winding up, our assets that secure secured debt will be available to pay obligations on the notes only after all indebtedness under such secured debt has been repaid in full from such assets. The notes will rank structurally junior to all indebtedness and other liabilities of our subsidiaries (including trade payables but excluding intercompany obligations and liabilities of a type not required to be reflected on a balance sheet of such subsidiaries in accordance with GAAP). We advise you that there may not be sufficient assets remaining to pay amounts due on any or all the notes then outstanding.

As of September 30, 2017, we and our subsidiaries had no consolidated indebtedness and our subsidiaries had $1.8 million of indebtedness and other liabilities (including trade payables, but excluding intercompany obligations and liabilities of a type not required to be reflected on a balance sheet of such subsidiaries in accordance with GAAP) to which the notes would have been structurally subordinated. After giving effect to the issuance of the notes (assuming no exercise of the underwriters’ over-allotment option) and the use of proceeds therefrom, our total consolidated indebtedness would have been $100 million.

The ability of our subsidiaries to pay dividends and make other payments to us is restricted by, among other things, applicable corporate and other laws and regulations as well as agreements to which our subsidiaries may become a party. We may not be able to pay the cash portions of any settlement amount upon conversion of the notes, or to pay cash for the fundamental change repurchase price upon a fundamental change if a holder requires us to repurchase notes as described below. See “Risk Factors—Risks Related to the Notes—We may not have the ability to raise the funds necessary to settle for cash conversions of the notes or to repurchase the notes for cash upon a fundamental change, and our future debt may contain limitations on our ability to pay cash upon conversion or repurchase of the notes.”

Optional Redemption On or After November 6, 2020

No “sinking fund” is provided for the notes, which means that we are not required to redeem or retire the notes periodically. Prior to November 6, 2020, the notes will not be redeemable. On or after November 6, 2020, we may redeem for cash all or any portion of the notes, at our option, if the last reported sale price of our common stock has been at least 130% of the conversion price then in effect for at least 20 trading days (whether or not consecutive), including the trading day immediately preceding the date on which we provide notice of redemption, during any 30 consecutive trading day period ending on, and including, the trading day immediately preceding the date on which we provide notice of redemption. In the case of any optional redemption, we will provide not less than 45 nor more than 60 scheduled trading days’ notice before the redemption date to the trustee, the paying agent and each holder of notes, and the redemption price will be equal to 100% of the principal amount of the notes to be redeemed, plus accrued and unpaid interest to, but excluding, the redemption date (unless the redemption date falls after a regular record date but on or prior to the immediately succeeding interest payment date, in which case we will pay the full amount of accrued and unpaid interest to the holder of record as of the close of business on such regular record date, and the redemption price will be equal to 100% of the principal amount of the notes to be redeemed). The redemption date must be a business day, and we may not specify a redemption date that falls on or after the 41st scheduled trading day immediately preceding the maturity date.

If we decide to redeem fewer than all of the outstanding notes and the notes are global notes, the notes to be redeemed will be selected by DTC in accordance with applicable DTC procedures. If the notes to be redeemed are not global notes then held by DTC, the notes to be redeemed will be selected by the trustee by a method that is similar to the selection procedures DTC would have applied if the notes had been global notes.

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If the trustee selects a portion of your note for partial redemption and you convert a portion of the same note, the converted portion will be deemed to be from the portion selected for redemption.

In the event of any redemption in part, we will not be required to register the transfer of or exchange for other notes any note so selected for redemption, in whole or in part, except the unredeemed portion of any note being redeemed in part.

No notes may be redeemed if the principal amount of the notes has been accelerated, and such acceleration has not been rescinded, on or prior to the redemption date (except in the case of an acceleration resulting from a default by us in the payment of the redemption price with respect to such notes).

Conversion Rights

General

Prior to the close of business on the business day immediately preceding May 1, 2022, the notes will be convertible only upon satisfaction of one or more of the conditions described under the headings “—Conversion upon Satisfaction of Sale Price Condition,” “—Conversion upon Satisfaction of Trading Price Condition,” “—Conversion upon Notice of Redemption” and “—Conversion upon Specified Corporate Events.” On or after May 1, 2022 until the close of business on the second scheduled trading day immediately preceding the maturity date, holders may convert all or any portion of their notes at the conversion rate at any time irrespective of the foregoing conditions.

The conversion rate will initially be              shares of common stock per $1,000 principal amount of notes (equivalent to an initial conversion price of approximately $             per share of common stock). Upon conversion of a note, we will satisfy our conversion obligation by paying or delivering, as the case may be, cash, shares of our common stock or a combination of cash and shares of our common stock, at our election, all as set forth below under “—Settlement upon Conversion.” If we satisfy our conversion obligation solely in cash or through payment and delivery, as the case may be, of a combination of cash and shares of our common stock, the amount of cash and shares of common stock, if any, due upon conversion will be based on a daily conversion value (as defined below) calculated on a proportionate basis for each trading day in a 40 trading day observation period (as defined below under “—Settlement upon Conversion”). The trustee will initially act as the conversion agent.

A holder may convert fewer than all of such holder’s notes so long as the notes converted are a multiple of $1,000 principal amount.

If we call notes for redemption, a holder of notes may convert all or any portion of its notes only until the close of business on the scheduled trading day immediately preceding the redemption date, unless we fail to pay the redemption price (in which case a holder of notes may convert such notes until the redemption price has been paid or duly provided for).

Upon conversion, you will not receive any separate cash payment for accrued and unpaid interest, if any, except as described below. We will not issue fractional shares of our common stock upon conversion of notes. Instead, we will pay cash in lieu of delivering any fractional share as described under “—Settlement upon Conversion.” Our payment and delivery, as the case may be, to you of the cash, shares of our common stock or a combination thereof, as the case may be, into which a note is convertible will be deemed to satisfy in full our obligation to pay:

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As a result, accrued and unpaid interest, if any, to, but not including, the relevant conversion date will be deemed to be paid in full rather than cancelled, extinguished or forfeited. Upon a conversion of notes into a combination of cash and shares of our common stock, accrued and unpaid interest will be deemed to be paid first out of the cash paid upon such conversion.

Notwithstanding the immediately preceding paragraph, if notes are converted after the close of business on a regular record date for the payment of interest, holders of such notes at the close of business on such regular record date will receive the full amount of interest payable on such notes on the corresponding interest payment date notwithstanding the conversion. Notes surrendered for conversion during the period from the close of business on any regular record date to the open of business on the immediately following interest payment date must be accompanied by funds equal to the amount of interest payable on the notes so converted; provided that no such payment need be made:

Therefore, for the avoidance of doubt, all record holders on the regular record date immediately preceding the maturity date will receive the full interest payment due on the maturity date in cash regardless of whether their notes have been converted following such regular record date.

If a holder converts notes, we will pay any documentary, stamp or similar issue or transfer tax due on any issuance of any shares of our common stock upon the conversion, unless the tax is due because the holder requests such shares to be issued in a name other than the holder’s name, in which case the holder will pay that tax.

Holders may surrender their notes for conversion under the following circumstances:

Conversion upon Satisfaction of Sale Price Condition

Prior to the close of business on the business day immediately preceding May 1, 2022, a holder may surrender all or any portion of its notes for conversion at any time during any calendar quarter commencing after the calendar quarter ending on March 31, 2018 (and only during such calendar quarter), if the last reported sale price of the common stock for at least 20 trading days (whether or not consecutive) during the period of 30 consecutive trading days ending on, and including, the last trading day of the immediately preceding calendar quarter is greater than or equal to 130% of the conversion price on each applicable trading day.

The “last reported sale price” of our common stock on any date means the closing sale price per share (or if no closing sale price is reported, the average of the bid and ask prices or, if more than one in either case, the average of the average bid and the average ask prices) on that date as reported in composite transactions for the principal U.S. national or regional securities exchange on which our common stock is traded. If our common stock is not listed for trading on a U.S. national or regional securities exchange on the relevant date, the “last reported sale price” will be the last quoted bid price for our common stock in the over-the-counter market on the relevant date as reported by OTC Markets Group Inc. or a similar organization. If our common stock is not so quoted, the “last reported sale price” will be the average of the mid-point of the last bid and ask prices for our common stock on the relevant date from each of at least three nationally recognized independent investment banking firms selected by us for this purpose. The “last reported sale price” will be determined without regard to after-hours trading or any other trading outside of regular trading session hours.

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“Trading day” means a day on which (i) trading in our common stock (or other security for which a closing sale price must be determined) generally occurs on The NASDAQ Global Market or, if our common stock (or such other security) is not then listed on The NASDAQ Global Market, on the principal other U.S. national or regional securities exchange on which our common stock (or such other security) is then listed or, if our common stock (or such other security) is not then listed on a U.S. national or regional securities exchange, on the principal other market on which our common stock (or such other security) is then traded, and (ii) a last reported sale price for our common stock (or closing sale price for such other security) is available on such securities exchange or market. If our common stock (or such other security) is not so listed or traded, “trading day” means a “business day.”

Conversion upon Satisfaction of Trading Price Condition

Prior to the close of business on the business day immediately preceding May 1, 2022, a holder of notes may surrender all or any portion of its notes for conversion at any time during the five business day period after any ten consecutive trading day period (the “measurement period”) in which the “trading price” per $1,000 principal amount of notes, as determined following a request by a holder of notes in accordance with the procedures described below, for each trading day of the measurement period was less than 98% of the product of the last reported sale price of our common stock and the conversion rate on each such trading day.

The “trading price” of the notes on any date of determination means the average of the secondary market bid quotations obtained by the bid solicitation agent for $5,000,000 principal amount of notes at approximately 3:30 p.m., New York City time, on such determination date from three independent nationally recognized securities dealers we select for this purpose; provided that if three such bids cannot reasonably be obtained by the bid solicitation agent but two such bids are obtained, then the average of the two bids shall be used, and if only one such bid can reasonably be obtained by the bid solicitation agent, that one bid shall be used. If the bid solicitation agent cannot reasonably obtain at least one bid for $5,000,000 principal amount of notes from a nationally recognized securities dealer, then the trading price per $1,000 principal amount of notes will be deemed to be less than 98% of the product of the last reported sale price of our common stock and the conversion rate. Any such determination will be conclusive absent manifest error. If (x) we are not acting as bid solicitation agent, and we do not, when we are required to, instruct the bid solicitation agent to obtain bids, or if we give such instruction to the bid solicitation agent, and the bid solicitation agent fails to make such determination, or (y) we are acting as bid solicitation agent and we fail to make such determination, then, in either case, the trading price per $1,000 principal amount of notes will be deemed to be less than 98% of the product of the last reported sale price of our common stock and the conversion rate on each trading day of such failure.

The bid solicitation agent (if other than us) shall have no obligation to determine the trading price per $1,000 principal amount of notes unless we have requested such determination; and we shall have no obligation to make such request (or, if we are acting as bid solicitation agent, we shall have no obligation to determine the trading price) unless a holder of at least $2,000,000 aggregate principal amount of notes provides us with reasonable evidence that the trading price per $1,000 principal amount of notes would be less than 98% of the product of the last reported sale price of our common stock and the conversion rate. At such time, we shall instruct the bid solicitation agent (if other than us) to determine, or if we are acting as bid solicitation agent, we shall determine, the trading price per $1,000 principal amount of notes beginning on the next trading day and on each successive trading day until the trading price per $1,000 principal amount of notes is greater than or equal to 98% of the product of the last reported sale price of our common stock and the conversion rate. If the trading price condition has been met, we will so notify the holders, the trustee and the conversion agent (if other than the trustee). If, at any time after the trading price condition has been met, the trading price per $1,000 principal amount of notes is greater than or equal to 98% of the product of the last reported sale price of our common stock and the conversion rate for such date, we will so notify the holders, the trustee and the conversion agent (if other than the trustee) and thereafter neither we nor the bid solicitation agent (if other than us) shall be required to solicit bids again until a new holder request is made as provided above.

We will initially act as the bid solicitation agent.

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Conversion upon Notice of Redemption

If we call any or all of the notes for redemption prior to the close of business on the business day immediately preceding May 1, 2022, holders may convert all or any portion of their notes at any time prior to the close of business on the scheduled trading day prior to the redemption date, even if the notes are not otherwise convertible at such time. After that time, the right to convert such notes on account of our delivery of the notice of redemption will expire, unless we default in the payment of the redemption price, in which case a holder of notes may convert all or any portion of its notes until the redemption price has been paid or duly provided for.

Conversion upon Specified Corporate Events

Certain Distributions

If, prior to the close of business on the business day immediately preceding May 1, 2022, we elect to:

then, in either case, we must notify the holders of the notes and the trustee at least 45 scheduled trading days prior to the ex-dividend date for such issuance or distribution (or, if later in the case of any such separation of rights issued pursuant to a stockholder rights plan, as soon as reasonably practicable after we become aware that such separation or triggering event has occurred or will occur). Once we have given such notice, holders may surrender all or any portion of their notes for conversion at any time until the earlier of the close of business on the business day immediately preceding the ex-dividend date for such issuance or distribution and our announcement that such issuance or distribution will not take place, even if the notes are not otherwise convertible at such time.

Certain Corporate Events

If a transaction or event that constitutes a “fundamental change” (as defined under “—Fundamental Change Permits Holders to Require Us to Repurchase Notes”) or a “make-whole fundamental change” (as defined under “—Increase in Conversion Rate upon Conversion upon a Make-whole Fundamental Change or Notice of Redemption”) occurs prior to the close of business on the business day immediately preceding May 1, 2022, regardless of whether a holder has the right to require us to repurchase the notes as described under “—Fundamental Change Permits Holders to Require Us to Repurchase Notes,” or if we are a party to a consolidation, merger, binding share exchange, or transfer or lease of all or substantially all of our assets that occurs prior to the close of business on the business day immediately preceding May 1, 2022, in each case, pursuant to which our common stock would be converted into cash, securities or other assets (other than a merger effected solely to change our jurisdiction of incorporation that does not otherwise constitute a fundamental change or a make-whole fundamental change), all or any portion of a holder’s notes may be surrendered for conversion at any time from or after the effective date for such transaction until 35 scheduled trading days after the effective date of the transaction (or, if we give notice after the effective date of such transaction, until 35

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trading days after the date we give notice) or, if such transaction also constitutes a fundamental change, until the related fundamental change repurchase date. We will notify holders, the trustee and the conversion agent (if other than the trustee) as promptly as practicable following the effective date of such transaction but in no event later than five business days after the effective date of such transaction.

Conversions On or After May 1, 2022

On or after May 1, 2022, a holder may convert all or any portion of its notes at any time prior to the close of business on the second scheduled trading day immediately preceding the maturity date regardless of the foregoing conditions.

Conversion Procedures

If you hold a beneficial interest in a global note, to convert you must comply with DTC’s procedures for converting a beneficial interest in a global note and, if required, pay funds equal to interest payable on the next interest payment date to which you are not entitled. As such, if you are a beneficial owner of the notes, you must allow for sufficient time to comply with DTC’s procedures if you wish to exercise your conversion rights. The exercise of such conversion rights shall be irrevocable.

If you hold a certificated note, to convert you must:

In either case, if a holder converts notes, we will pay any documentary, stamp or similar issue or transfer tax on the issuance of any shares of our common stock upon conversion of the notes, unless the tax is due because the holder requests such shares to be issued in a name other than the holder’s name, in which case the holder will pay the tax.

We refer to the date you comply with the relevant procedures for conversion described above as the “conversion date.”

If a holder has already delivered a repurchase notice as described under “—Fundamental Change Permits Holders to Require Us to Repurchase Notes” with respect to a note, the holder may not surrender that note for conversion until the holder has withdrawn the repurchase notice in accordance with the relevant provisions of the indenture. If a holder submits its notes for required repurchase, the holder’s right to withdraw the repurchase notice and convert the notes that are subject to repurchase will terminate at the close of business on the business day immediately preceding the relevant fundamental change repurchase date.

Settlement upon Conversion

Upon conversion, we may choose to pay or deliver, as the case may be, either cash (“cash settlement”), shares of our common stock (“physical settlement”) or a combination of cash and shares of our common stock (“combination settlement”), as described below. We refer to each of these settlement methods as a “settlement method.”

All conversions for which the relevant conversion date occurs after our issuance of a notice of redemption with respect to the notes and prior to the related redemption date and all conversions for which the relevant

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conversion date occurs on or after May 1, 2022 will be settled using the same settlement method. Except for any conversions for which the relevant conversion date occurs after our issuance of a notice of redemption but prior to the related redemption date, and any conversions for which the relevant conversion date occurs on or after May 1, 2022, we will use the same settlement method for all conversions with the same conversion date, but we will not have any obligation to use the same settlement method with respect to conversions with different conversion dates. That is, we may choose for notes converted on one conversion date to settle conversions in physical settlement, and choose for notes converted on another conversion date cash settlement or combination settlement.

If we elect a settlement method, we will inform holders so converting through the trustee of the settlement method we have selected no later than the close of business on the trading day immediately following the related conversion date (or in the case of any conversions for which the relevant conversion date occurs (i) after the date of issuance of a notice of redemption as described under “—Optional Redemption On or After November 6, 2020” and prior to the related redemption date, in such notice of redemption or (ii) on or after May 1, 2022, no later than May 1, 2022). If we do not timely elect a settlement method, we will no longer have the right to elect cash settlement or physical settlement with respect to any conversion on such conversion date or during such period, and we will be deemed to have elected combination settlement in respect of our conversion obligation, as described below, and the specified dollar amount (as defined below) per $1,000 principal amount of notes will be equal to $1,000. If we elect combination settlement, but we do not timely notify converting holders of the specified dollar amount per $1,000 principal amount of notes to be converted, such specified dollar amount will be deemed to be $1,000. It is our current intent and policy to settle conversions through combination settlement with a specified dollar amount per $1,000 principal amount of notes of $1,000.

By notice to all holders of the notes, we may, prior to May 1, 2022, at our option, irrevocably elect to satisfy our conversion obligation with respect to the notes through combination settlement with a specified dollar amount per $1,000 principal amount of notes of $1,000 for all conversion dates occurring subsequent to delivery of such notice.

Settlement amounts will be computed as follows:

The “daily settlement amount,” for each of the 40 consecutive trading days during the observation period, shall consist of:

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The “daily conversion value” means, for each of the 40 consecutive trading days during the observation period, 2.5% of the product of (1) the conversion rate on such trading day and (2) the daily VWAP for such trading day.

The “daily VWAP” means, for each of the 40 consecutive trading days during the relevant observation period, the per share volume-weighted average price as displayed under the heading “Bloomberg VWAP” on Bloomberg page “EVBG <equity> AQR” (or its equivalent successor if such page is not available) in respect of the period from the scheduled open of trading until the scheduled close of trading of the primary trading session on such trading day (or if such volume-weighted average price is unavailable, the market value of one share of our common stock on such trading day determined, using a volume-weighted average method, by a nationally recognized independent investment banking firm retained for this purpose by us). The “daily VWAP” will be determined without regard to after-hours trading or any other trading outside of the regular trading session trading hours.

The “observation period” with respect to any note surrendered for conversion means:

For the purposes of determining amounts due upon conversion only, “trading day” means a day on which (i) there is no “market disruption event” (as defined below) and (ii) trading in our common stock generally occurs on The NASDAQ Global Market or, if our common stock is not then listed on The NASDAQ Global Market, on the principal other U.S. national or regional securities exchange on which our common stock is then listed or, if our common stock is not then listed on a U.S. national or regional securities exchange, on the principal other market on which our common stock is then listed or admitted for trading. If our common stock is not so listed or admitted for trading, “trading day” means a “business day.”

“Scheduled trading day” means a day that is scheduled to be a trading day on the principal U.S. national or regional securities exchange or market on which our common stock is listed or admitted for trading. If our common stock is not so listed or admitted for trading, “scheduled trading day” means a “business day.”

For the purposes of determining amounts due upon conversion, “market disruption event” means (i) a failure by the primary U.S. national or regional securities exchange or market on which our common stock is listed or admitted for trading to open for trading during its regular trading session or (ii) the occurrence or existence prior to 1:00 p.m., New York City time, on any scheduled trading day for our common stock for more than one half-hour period in the aggregate during regular trading hours of any suspension or limitation imposed on trading (by reason of movements in price exceeding limits permitted by the relevant stock exchange or otherwise) in our common stock or in any options contracts or futures contracts relating to our common stock.

Except as described under “—Increase in Conversion Rate upon Conversion upon a Make-whole Fundamental Change or Notice of Redemption” and “—Recapitalizations, Reclassifications and Changes of Our Common Stock,” we will deliver the consideration due in respect of conversion on the second business day immediately following the relevant conversion date, if we elect physical settlement, or on the second business day immediately following the last trading day of the relevant observation period, in the case of any other settlement method.

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We will pay cash in lieu of delivering any fractional share of common stock issuable upon conversion based on the daily VWAP for the relevant conversion date (in the case of physical settlement) or based on the daily VWAP for the last trading day of the relevant observation period (in the case of combination settlement).

Each conversion will be deemed to have been effected as to any notes surrendered for conversion on the conversion date; provided, however, that the person in whose name any shares of our common stock shall be issuable upon such conversion will become the holder of record of such shares as of the close of business on such conversion date (in the case of physical settlement) or the last trading day of the relevant observation period (in the case of combination settlement).

Exchange in Lieu of Conversion

When a holder surrenders its notes for conversion, we may, at our election (an “exchange election”), direct the conversion agent to surrender, on or prior to the business day immediately following the conversion date, such notes to one or more financial institutions designated by us for exchange in lieu of conversion. In order to accept any notes surrendered for conversion, the designated financial institution(s) must agree to timely pay or deliver, as the case may be, in exchange for such notes, cash, shares of our common stock, or a combination of cash and shares of our common stock, at our election, that would otherwise be due upon conversion as described above under “—Conversion rights—Settlement upon conversion” (the “conversion consideration”). If we make an exchange election, we will, by the close of business on the business day following the relevant conversion date, notify in writing the trustee, the conversion agent (if other than the trustee) and the holder surrendering its notes for conversion that we have made the exchange election and we will notify the designated financial institution(s) of the relevant deadline for delivery of the consideration due upon conversion and the type of conversion consideration to be paid and/or delivered, as the case may be.

Any notes exchanged by the designated financial institution(s) will remain outstanding, subject to applicable DTC procedures. If the financial institution(s) agree(s) to accept any notes for exchange but does not timely pay and/or deliver, as the case may be, the related conversion consideration, or if such designated financial institution does not accept the notes for exchange, we will pay or deliver, as the case may be, the relevant conversion consideration, as, and at the time, required pursuant to the indenture as if we had not made the exchange election.

Our designation of any financial institution(s) to which the notes may be submitted for exchange does not require such financial institution(s) to accept any notes.

Conversion Rate Adjustments

The conversion rate will be adjusted as described below, except that we will not make any adjustments to the conversion rate if holders of the notes participate (other than in the case of (x) a share split or share combination or (y) a tender or exchange offer), at the same time and upon the same terms as holders of our common stock and solely as a result of holding the notes, in any of the transactions described below without having to convert their notes as if they held a number of shares of common stock equal to the conversion rate, multiplied by the principal amount (expressed in thousands) of notes held by such holder.

(1) If we exclusively issue shares of our common stock as a dividend or distribution on shares of our common stock, or if we effect a share split or share combination, the conversion rate will be adjusted based on the following formula:

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Any adjustment made under this clause (1) shall become effective immediately after the open of business on the ex-dividend date for such dividend or distribution, or immediately after the open of business on the effective date for such share split or share combination, as applicable. If any dividend or distribution of the type described in this clause (1) is declared but not so paid or made, the conversion rate shall be immediately readjusted, effective as of the date our board of directors or a committee thereof determines not to pay such dividend or distribution, to the conversion rate that would then be in effect if such dividend or distribution had not been declared.

(2) If we distribute to all or substantially all holders of our common stock any rights, options or warrants (other than pursuant to a stockholder rights plan) entitling them, for a period of not more than 60 calendar days after the announcement date of such distribution, to subscribe for or purchase shares of our common stock at a price per share that is less than the average of the last reported sale prices of our common stock for the 10 consecutive trading day period ending on, and including, the trading day immediately preceding the date of announcement of such distribution, the conversion rate will be increased based on the following formula:

Any increase made under this clause (2) will be made successively whenever any such rights, options or warrants are distributed and shall become effective immediately after the open of business on the ex-dividend date for such distribution. To the extent that shares of common stock are not delivered after the expiration of such rights, options or warrants, the conversion rate shall be decreased to the conversion rate that would then be in

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effect had the increase with respect to the distribution of such rights, options or warrants been made on the basis of delivery of only the number of shares of common stock actually delivered. If such rights, options or warrants are not so distributed, the conversion rate shall be decreased to the conversion rate that would then be in effect if such ex-dividend date for such distribution had not occurred.

For the purpose of this clause (2) and for the purpose of the first bullet point under “—Conversion upon Specified Corporate Events —Certain Distributions,” in determining whether any rights, options or warrants entitle the holders to subscribe for or purchase shares of the common stock at less than such average of the last reported sale prices for the 10 consecutive trading day period ending on, and including, the trading day immediately preceding the date of announcement of such distribution, and in determining the aggregate offering price of such shares of common stock, there shall be taken into account any consideration received by us for such rights, options or warrants and any amount payable on exercise or conversion thereof, the value of such consideration, if other than cash, to be determined by us in good faith and in a commercially reasonable manner.

(3) If we distribute shares of our capital stock, evidences of our indebtedness, other assets or property of ours or rights, options or warrants to acquire our capital stock or other securities, to all or substantially all holders of our common stock, excluding:

then the conversion rate will be increased based on the following formula:

Any increase made under the portion of this clause (3) above will become effective immediately after the open of business on the ex-dividend date for such distribution. If such distribution is not so paid or made, the conversion rate shall be decreased to be the conversion rate that would then be in effect if such distribution had not been declared. In the case of any distribution of rights, options or warrants, to the extent such rights options or warrants expire unexercised, the applicable conversion rate shall be immediately readjusted to the applicable

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conversion rate that would then be in effect had the increase made for the distribution of such rights, options or warrants been made on the basis of delivery of only the number of shares of our common stock actually delivered upon exercise of such rights, options or warrants. Notwithstanding the foregoing, if “FMV” (as defined above) is equal to or greater than “SP₀” (as defined above), in lieu of the foregoing increase, each holder of a note shall receive, in respect of each $1,000 principal amount thereof, at the same time and upon the same terms as holders of our common stock, the amount and kind of our capital stock, evidences of our indebtedness, other assets or property of ours or rights, options or warrants to acquire our capital stock or other securities that such holder would have received if such holder owned a number of shares of common stock equal to the conversion rate in effect on the ex-dividend date for the distribution.

With respect to an adjustment pursuant to this clause (3) where there has been a payment of a dividend or other distribution on our common stock of shares of capital stock of any class or series, or similar equity interest, of or relating to a subsidiary or other business unit, that are, or, when issued, will be, listed or admitted for trading on a U.S. national securities exchange, which we refer to as a “spin-off,” the conversion rate will be increased based on the following formula:

The increase to the conversion rate under the preceding paragraph will occur at the close of business on the last trading day of the valuation period; provided that (x) in respect of any conversion of notes for which physical settlement is applicable, if the relevant conversion date occurs during the valuation period, the reference to “10” in the preceding paragraph shall be deemed replaced with such lesser number of trading days as have elapsed between the ex-dividend date for such spin-off and such conversion date in determining the conversion rate and (y) in respect of any conversion of notes for which cash settlement or combination settlement is applicable, for any trading day that falls within the relevant observation period for such conversion and within the valuation period, the reference to “10” in the preceding paragraph shall be deemed replaced with such lesser number of trading days as have elapsed between the ex-dividend date for such spin-off and such trading day in determining the conversion rate as of such trading day. If any dividend or distribution that constitutes a spin-off is declared but not so paid or made, the conversion rate shall be immediately decreased, effective as of the date our board of directors or a committee thereof determines not to pay or make such dividend or distribution, to the conversion rate that would then be in effect if such dividend or distribution had not been declared or announced.

(4) If we make any cash dividend or distribution to all or substantially all holders of our common stock, the conversion rate will be adjusted based on the following formula:

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Any increase made under this clause (4) shall become effective immediately after the open of business on the ex-dividend date for such dividend or distribution. If such dividend or distribution is not so paid, the conversion rate shall be decreased, effective as of the date our board of directors or a committee thereof determines not to make or pay such dividend or distribution, to be the conversion rate that would then be in effect if such dividend or distribution had not been declared. Notwithstanding the foregoing, if “C” (as defined above) is equal to or greater than “SP₀” (as defined above), in lieu of the foregoing increase, each holder of a note shall receive, for each $1,000 principal amount of notes, at the same time and upon the same terms as holders of shares of our common stock, the amount of cash that such holder would have received if such holder owned a number of shares of our common stock equal to the conversion rate on the ex-dividend date for such cash dividend or distribution.

(5) If we or any of our subsidiaries make a payment in respect of a tender or exchange offer for our common stock that is subject to the then-applicable tender offer rules under the Exchange Act (other than any odd-lot tender offer), to the extent that the cash and value of any other consideration included in the payment per share of common stock exceeds the average of the last reported sale prices of our common stock over the 10 consecutive trading day period commencing on, and including, the trading day next succeeding the last date on which tenders or exchanges may be made pursuant to such tender or exchange offer, the conversion rate will be increased based on the following formula:

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The increase to the conversion rate under the preceding paragraph will occur at the close of business on the 10th trading day immediately following, and including, the trading day next succeeding the date such tender or exchange offer expires; provided that (x) in respect of any conversion of notes for which physical settlement is applicable, if the relevant conversion date occurs during the 10 trading days immediately following, and including, the trading day next succeeding the expiration date of any tender or exchange offer, references to “10” or “10th” in the preceding paragraph shall be deemed replaced with such lesser number of trading days as have elapsed from, and including, the trading day next succeeding such expiration date of such tender or exchange offer and to, and including, such conversion date in determining the conversion rate and (y) in respect of any conversion of notes for which cash settlement or combination settlement is applicable, for any trading day that falls within the relevant observation period for such conversion and within the 10 trading days immediately following, and including, the trading day next succeeding the expiration date of any tender or exchange offer, references to “10” or “10th” in the preceding paragraph shall be deemed replaced with such lesser number of trading days as have elapsed from, and including, the trading day next succeeding such expiration date of such tender or exchange offer and such trading day in determining the conversion rate as of such trading day.

If we are obligated to purchase shares of our common stock pursuant to any such tender or exchange offer described in clause (5) but are permanently prevented by applicable law from effecting any such purchase or all such purchases are rescinded, the applicable conversion rate will be readjusted to be the conversion rate that would then be in effect if such tender or exchange offer had not been made or had been made only in respect of the purchases that have been made.

Notwithstanding the foregoing, if a conversion rate adjustment becomes effective on any ex-dividend date as described above, and a holder that has converted its notes on or after such ex-dividend date and on or prior to the related record date would be treated as the record holder of shares of our common stock as of the related conversion date as described under “—Settlement upon Conversion” based on an adjusted conversion rate for such ex-dividend date, then, notwithstanding the foregoing conversion rate adjustment provisions, the conversion rate adjustment relating to such ex-dividend date will not be made for such converting holder. Instead, such holder will be treated as if such holder were the record owner of the shares of our common stock on an unadjusted basis and participate in the related dividend, distribution or other event giving rise to such adjustment.

Except as stated herein, we will not adjust the conversion rate for the issuance of shares of our common stock or any securities convertible into or exchangeable for shares of our common stock or the right to purchase shares of our common stock or such convertible or exchangeable securities.

As used in this section, “ex-dividend date” means the first date on which the shares of our common stock trade on the applicable exchange or in the applicable market, regular way, without the right to receive the issuance, dividend or distribution in question, from us or, if applicable, from the seller of our common stock on such exchange or market (in the form of due bills or otherwise) as determined by such exchange or market, and “effective date” means the first date on which the shares of our common stock trade on the applicable exchange or in the applicable market, regular way, reflecting the relevant share split or share combination, as applicable. For the avoidance of doubt, any alternative trading convention on the applicable exchange or market in respect of shares of our common stock under a separate ticker symbol or CUSIP number will not be considered “regular way” for this purpose.

As used in this section, “record date” means, with respect to any dividend, distribution or other transaction or event in which the holders of our common stock (or other applicable security) have the right to receive any cash, securities or other property or in which our common stock (or such other security) is exchanged for or

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converted into any combination of cash, securities or other property, the date fixed for determination of holders of our common stock (or such other security) entitled to receive such cash, securities or other property (whether such date is fixed by our board of directors or a duly authorized committee thereof, statute, contract or otherwise).

We are permitted to increase the conversion rate of the notes by any amount for a period of at least 20 business days if we determine that such increase would be in our best interest. We may also (but are not required to) increase the conversion rate to avoid or diminish income tax to holders of our common stock or rights to purchase shares of our common stock in connection with a dividend or distribution of shares (or rights to acquire shares) or similar event.

A holder may, in some circumstances, including a distribution of cash dividends to holders of our shares of common stock, be deemed to have received a distribution subject to U.S. federal income tax as a result of an adjustment or the nonoccurrence of an adjustment to the conversion rate. For a discussion of the U.S. federal income tax treatment of an adjustment to the conversion rate, see “Certain U.S. Federal Income Tax Considerations.”

If we have a rights plan in effect upon conversion of the notes into common stock, you will receive, in addition to any shares of common stock received in connection with such conversion, the rights under the rights plan. However, if, prior to any conversion, the rights have separated from the shares of common stock in accordance with the provisions of the applicable rights plan, the conversion rate will be adjusted at the time of separation as if we distributed to all or substantially all holders of our common stock, shares of our capital stock, evidences of indebtedness, assets, property, rights, options or warrants as described in clause (3) above, subject to readjustment in the event of the expiration, termination or redemption of such rights.

Notwithstanding any of the foregoing, the conversion rate will not be adjusted:

Adjustments to the conversion rate will be calculated to the nearest 1/10,000th of a share.

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If an adjustment to the conversion rate otherwise required by the provisions described above would result in a change of less than 1% to the conversion rate, then, notwithstanding the foregoing, we may, at our election, defer and carry forward such adjustment, except that all such deferred adjustments must be given effect immediately upon the earliest to occur of the following: (i) when all such deferred adjustments would result in an aggregate change of at least 1% to the conversion rate, (ii) on the conversion date for any notes (in the case of physical settlement), (iii) on each trading day of any observation period related to any conversion of notes (in the case of cash settlement or combination settlement) and (iv) on the effective date of any make-whole fundamental change, in each case, unless the adjustment has already been made.

Recapitalizations, Reclassifications and Changes of Our Common Stock

In the case of:

in each case, as a result of which our common stock would be converted into, or exchanged for, stock, other securities, other property or assets (including cash or any combination thereof), then, at and after the effective time of the transaction, the right to convert each $1,000 principal amount of notes will be changed into a right to convert such principal amount of notes into the kind and amount of shares of stock, other securities or other property or assets (including cash or any combination thereof) that a holder of a number of shares of common stock equal to the conversion rate immediately prior to such transaction would have owned or been entitled to receive (the “reference property”) upon such transaction. However, at and after the effective time of the transaction, (i) we will continue to have the right to determine the form of consideration to be paid or delivered, as the case may be, upon conversion of notes, as set forth under “—Settlement upon Conversion” and (ii) (x) any amount payable in cash upon conversion of the notes as set forth under “—Settlement upon Conversion” will continue to be payable in cash, (y) any shares of our common stock that we would have been required to deliver upon conversion of the notes as set forth under “—Settlement upon Conversion” will instead be deliverable in the amount and type of reference property that a holder of that number of shares of our common stock would have received in such transaction and (z) the daily VWAP will be calculated based on the value of a unit of reference property that a holder of one share of our common stock would have received in such transaction. If the transaction causes our common stock to be converted into, or exchanged for, the right to receive more than a single type of consideration (determined based in part upon any form of stockholder election), the reference property into which the notes will be convertible will be deemed to be (i) the weighted average of the types and amounts of consideration received by the holders of our common stock that affirmatively make such an election or (ii) if no holders of our common stock affirmatively make such an election, the types and amounts of consideration actually received by the holders of our common stock. If the holders of our common stock receive only cash in such transaction, then for all conversions that occur after the effective date of such transaction (i) the consideration due upon conversion of each $1,000 principal amount of notes shall be solely cash in an amount equal to the conversion rate in effect on the conversion date (as may be increased as described under “—Increase in Conversion Rate upon Conversion upon a Make-whole Fundamental Change or Notice of Redemption”), multiplied by the price paid per share of common stock in such transaction and (ii) we will satisfy our conversion obligation by paying cash to converting holders on the second business day immediately following the conversion date. We will notify holders, the trustee and the conversion agent (if other than the trustee) of the weighted average as soon as practicable after such determination is made.

The supplemental indenture providing that the notes will be convertible into reference property (other than cash) will also provide for anti-dilution and other adjustments that are as nearly equivalent as possible to the

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adjustments described under “—Conversion Rate Adjustments” above. If the reference property in respect of any such transaction includes shares of stock, securities or other property or assets (other than cash and/or cash equivalents) of a company other than us or the successor or purchasing corporation, as the case may be, in such transaction, such other company, if an affiliate of us or the successor or purchasing corporation, will also execute such supplemental indenture, and such supplemental indenture will contain such additional provisions to protect the interests of the holders, including the right of holders to require us to repurchase their notes upon a fundamental change as described under “—Fundamental Change Permits Holders to Require Us to Repurchase Notes” below, as we in good faith reasonably consider necessary by reason of the foregoing. We will agree in the indenture not to become a party to any such transaction unless its terms are consistent with the foregoing.

Adjustments of Prices

Whenever any provision of the indenture requires us to calculate the last reported sale prices, the daily VWAPs, the daily conversion values or the daily settlement amounts over a span of multiple days (including, without limitation, an observation period and the period, if any, for determining “stock price” for purposes of a make-whole fundamental change or redemption), we will make appropriate adjustments in good faith and in a commercially reasonable manner to each to account for any adjustment to the conversion rate that becomes effective, or any event requiring an adjustment to the conversion rate where the ex-dividend date, effective date or expiration date of the event occurs, at any time during the period when the last reported sale prices, the daily VWAPs, the daily conversion values or the daily settlement amounts are to be calculated.

For the avoidance of doubt, the adjustments made pursuant to the foregoing paragraph will be made, solely to the extent we determine in good faith and in a commercially reasonable manner that any such adjustment is appropriate, without duplication of any adjustment made pursuant to the provision set forth under “—Conversion Rate Adjustments.”

Increase in Conversion Rate upon Conversion upon a Make-whole Fundamental Change or Notice of Redemption

If (i) the “effective date” (as defined below) of a “fundamental change” (as defined below and determined after giving effect to any exceptions to or exclusions from such definition, but without regard to the proviso in clause (2) of the definition thereof, a “make-whole fundamental change”) occurs prior to the maturity date of the notes or (ii) we give a notice of redemption with respect to any or all of the notes as provided for under “—Optional Redemption On or After November 6, 2020” and, in each case, a holder elects to convert its notes in connection with such make-whole fundamental change or redemption notice, as applicable, we will, under certain circumstances, increase the conversion rate for the notes so surrendered for conversion by a number of additional shares of common stock (the “additional shares”), as described below. A conversion of notes will be deemed for these purposes to be “in connection with” such make-whole fundamental change if the relevant notice of conversion of the notes is received by the conversion agent from, and including, the effective date of the make-whole fundamental change up to, and including, the business day immediately prior to the related fundamental change repurchase date (or, in the case of a make-whole fundamental change that would have been a fundamental change but for the proviso in clause (2) of the definition thereof, the 35th trading day immediately following the effective date of such make-whole fundamental change) (such period, the “make-whole fundamental change period”). A conversion of notes will be deemed for these purposes to be “in connection with” a redemption notice if the notice of conversion of the notes is received by the conversion agent from, and including, the date of the redemption notice until the close of business on the scheduled trading day immediately preceding the redemption date.

Upon surrender of notes for conversion in connection with a make-whole fundamental change or redemption notice, we will, at our option, satisfy our conversion obligation by physical settlement, cash settlement or combination settlement, as described under “—Conversion Rights—Settlement upon Conversion.” However, if the consideration for our common stock in any make-whole fundamental change described in clause

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(2) of the definition of fundamental change is composed entirely of cash, for any conversion of notes following the effective date of such make-whole fundamental change, the conversion obligation will be calculated based solely on the “stock price” (as defined below) for the transaction and will be deemed to be an amount of cash per $1,000 principal amount of converted notes equal to the conversion rate (including any increase to reflect the additional shares as described in this section), multiplied by such stock price. In such event, the conversion obligation will be determined and paid to holders in cash on the second business day following the conversion date. We will notify holders of the effective date of any make-whole fundamental change no later than five business days after such effective date.

The number of additional shares, if any, by which the conversion rate will be increased will be determined by reference to the table below, based on the date on which the make-whole fundamental change occurs or becomes effective or the date of the redemption notice, as the case may be (in each case, the “effective date”) and the price paid (or deemed to be paid) per share of our common stock in the make-whole fundamental change or with respect to the redemption, as the case may be (the “stock price”). If the holders of our common stock receive in exchange for their common stock only cash in a make-whole fundamental change described in clause (2) of the definition of fundamental change, the stock price will be the cash amount paid per share. Otherwise, the stock price will be the average of the last reported sale prices of our common stock over the five consecutive trading day period ending on, and including, the trading day immediately preceding the effective date of the make-whole fundamental change or the date of the redemption notice, as the case may be.

The stock prices set forth in the column headings of the table below will be adjusted as of any date on which the conversion rate of the notes is otherwise adjusted. The adjusted stock prices will equal the stock prices immediately prior to such adjustment, multiplied by a fraction, the numerator of which is the conversion rate immediately prior to the adjustment giving rise to the stock price adjustment and the denominator of which is the conversion rate as so adjusted. The number of additional shares as set forth in the table below will be adjusted in the same manner and at the same time as the conversion rate as set forth under “—Conversion Rate Adjustments.”

The following table sets forth the number of additional shares by which the conversion rate will be increased per $1,000 principal amount of notes for each stock price and effective date set forth below:

The exact stock price and effective date may not be set forth in the table above, in which case

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Notwithstanding the foregoing, in no event will the conversion rate per $1,000 principal amount of notes exceed             shares of common stock, subject to adjustment in the same manner as the conversion rate as set forth under “—Conversion Rate Adjustments.”

Our obligation to increase the conversion rate for notes converted in connection with a make-whole fundamental change or notice of redemption could be considered a penalty, in which case the enforceability thereof would be subject to general principles of reasonableness and equitable remedies.

Fundamental Change Permits Holders to Require Us to Repurchase Notes

If a “fundamental change” (as defined below in this section) occurs at any time, holders will have the right, at their option, to require us to repurchase for cash all of their notes, or any portion of the principal amount thereof that is equal to $1,000 or a multiple of $1,000. The fundamental change repurchase date will be a date specified by us that is not less than 20 or more than 35 business days following the date of our fundamental change notice as described below.

The fundamental change repurchase price we are required to pay will be equal to 100% of the principal amount of the notes to be repurchased, plus accrued and unpaid interest to, but excluding, the fundamental change repurchase date (unless the fundamental change repurchase date falls after a regular record date but on or prior to the interest payment date to which such regular record date relates, in which case we will instead pay the full amount of accrued and unpaid interest to the holder of record on such regular record date, and the fundamental change repurchase price will be equal to 100% of the principal amount of the notes to be repurchased).

A “fundamental change” will be deemed to have occurred at the time after the notes are originally issued if any of the following occurs:

(1) a “person” or “group” within the meaning of Section 13(d) of the Exchange Act, other than us, our wholly owned subsidiaries and our and their employee benefit plans, files a Schedule TO (or any successor schedule, form or report) or any schedule, form or report under the Exchange Act that discloses that such person or group has become the direct or indirect “beneficial owner,” as defined in Rule 13d-3 under the Exchange Act, of our common stock representing more than 50% of the voting power of our common stock, unless such beneficial ownership arises solely as a result of a revocable proxy delivered in response to a public proxy or consent solicitation made pursuant to the applicable rules and regulations under the Exchange Act; provided that no person or group shall be deemed to be the beneficial owner of any securities tendered pursuant to a tender or exchange offer made by or on behalf of such person or group until such tendered securities are accepted for purchase or exchange under such offer;

(2) the consummation of (A) any recapitalization, reclassification or change of our common stock (other than changes resulting from a subdivision or combination or solely a change in par value) as a result of which our common stock would be converted into, or exchanged for, stock, other securities, other property or assets; (B) any share exchange, consolidation or merger of us pursuant to which our common stock will be converted into cash, securities or other property or assets; or (C) any sale, lease or other transfer in one transaction or a series of transactions of all or substantially all of the consolidated assets of us and our subsidiaries, taken as a whole, to any person other than one or more of our direct or indirect wholly owned subsidiaries; provided, however, that a transaction described in clauses (A) or (B) in which the holders of all classes of our common equity immediately prior to such transaction own, directly or indirectly, more than 50% of all classes of common equity of the continuing or surviving corporation or transferee or the parent thereof immediately after such transaction in substantially the same proportions (relative to each other) as such ownership immediately prior to such transaction shall not be a fundamental change pursuant to this clause (2);

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(3) our stockholders approve any plan or proposal for the liquidation or dissolution of us; or

(4) our common stock (or other common stock underlying the notes) ceases to be listed or quoted on any of The New York Stock Exchange, The NASDAQ Global Select Market or The NASDAQ Global Market (or any of their respective successors).

For purposes of the definition of “fundamental change” above, any transaction that constitutes a fundamental change pursuant to both clause (1) and clause (2) of such definition shall be deemed a fundamental change solely under clause (2) of such definition.

A transaction or transactions described in clause (1) or clause (2) above will not constitute a fundamental change, however, if at least 90% of the consideration received or to be received by our common stockholders, excluding cash payments for fractional shares and cash payments made in respect of dissenters’ appraisal rights, in connection with such transaction or transactions consists of shares of common stock that are listed or quoted on any of The New York Stock Exchange, The NASDAQ Global Select Market or The NASDAQ Global Market (or any of their respective successors) or will be so listed or quoted when issued or exchanged in connection with such transaction or transactions and as a result of such transaction or transactions the notes become convertible into such consideration, excluding cash payments for fractional shares and cash payments made in respect of dissenters’ appraisal rights (subject to the provisions set forth above under “—Conversion Rights—Settlement upon Conversion”).

If any transaction in which our common stock is replaced by the securities of another entity occurs, following completion of any related make-whole fundamental change period (or, in the case of a transaction that would have been a fundamental change or a make-whole fundamental change but for the immediately preceding paragraph, following the effective date of such transaction), references to us in the definition of “fundamental change” above shall instead be references to such other entity.

On or before the 20th day after the occurrence of a fundamental change, we will provide to all holders of the notes and the trustee and paying agent a notice of the occurrence of the fundamental change and of the resulting repurchase right. Such notice shall state, among other things:

Notwithstanding anything to the contrary above, we will not be required to repurchase or make an offer to repurchase the notes upon a fundamental change if a third party makes such an offer in the same manner, at the same time and otherwise in compliance with the requirements for an offer made by us as set forth in the indenture and such third party purchases all notes properly surrendered and not validly withdrawn under its offer in the same manner, at the same time and otherwise in compliance with the requirements for an offer made by us as set forth in the indenture.

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To exercise the fundamental change repurchase right, holders of certificated notes must deliver, on or before the business day immediately preceding the fundamental change repurchase date, the notes to be repurchased, duly endorsed for transfer, together with a written repurchase notice, to the paying agent. Each repurchase notice must state:

If the notes are not in certificated form, holders must surrender their notes in accordance with applicable DTC procedures.

Holders of certificated notes may withdraw any repurchase notice (in whole or in part) by a written notice of withdrawal delivered to the paying agent prior to the close of business on the business day immediately preceding the fundamental change repurchase date. The notice of withdrawal shall state:

If the notes are not in certificated form, holders must surrender their notes in accordance with applicable DTC procedures.

We will be required to repurchase the notes on the fundamental change repurchase date. Holders who have exercised the repurchase right will receive payment of the fundamental change repurchase price on the later of (i) the fundamental change repurchase date and (ii) the time of book-entry transfer or the delivery of the notes. If the paying agent holds money sufficient to pay the fundamental change repurchase price of the notes on the fundamental change repurchase date, then, with respect to the notes that have been properly surrendered for repurchase and have not been validly withdrawn:

In connection with any repurchase offer pursuant to a fundamental change repurchase notice, we will, if required:

in each case, so as to permit the rights and obligations under this “—Fundamental Change Permits Holders to Require Us to Repurchase Notes” to be exercised in the time and in the manner specified in the indenture.

To the extent that, as a result of a change in law occurring after the first date on which the notes are issued, the provisions of any securities laws or regulations conflict with the provisions of the indenture relating to our

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obligations to purchase the notes upon a fundamental change, we will comply with the applicable securities laws and regulations and will not be deemed to have breached our obligations under such provisions of the indenture by virtue of such conflict.

No notes may be repurchased on any date at the option of holders upon a fundamental change if the principal amount of the notes has been accelerated, and such acceleration has not been rescinded, on or prior to such date (except in the case of an acceleration resulting from a default by us in the payment of the fundamental change repurchase price with respect to such notes).

The repurchase rights of the holders could discourage a potential acquirer of us. The fundamental change repurchase feature, however, is not the result of management’s knowledge of any specific effort to obtain control of us by any means or part of a plan by management to adopt a series of anti-takeover provisions.

The term fundamental change is limited to specified transactions and may not include other events that might adversely affect our financial condition. In addition, the requirement that we offer to repurchase the notes upon a fundamental change may not protect holders in the event of a highly leveraged transaction, reorganization, merger or similar transaction involving us.

The definition of fundamental change includes a phrase relating to the sale, lease or other transfer of “all or substantially all” of our consolidated assets. There is no precise, established definition of the phrase “substantially all” under applicable law. Accordingly, the ability of a holder of the notes to require us to repurchase its notes as a result of the sale, lease or other transfer of less than all of our assets may be uncertain.

If a fundamental change were to occur, we may not have enough funds to pay the fundamental change repurchase price. Our ability to repurchase the notes for cash may be limited by restrictions on our ability to obtain funds for such repurchase through dividends from our subsidiaries, the terms of our then existing borrowing arrangements or otherwise. See “Risk Factors—Risks Related to the Notes—We may not have the ability to raise the funds necessary to settle for cash conversions of the notes or to repurchase the notes for cash upon a fundamental change, and our future debt may contain limitations on our ability to pay cash upon conversion or repurchase of the notes.” If we fail to repurchase the notes when required following a fundamental change, we will be in default under the indenture. In addition, we have, and may in the future incur, other indebtedness with similar change in control provisions permitting our holders to accelerate or to require us to repurchase our indebtedness upon the occurrence of similar events or on some specific dates.

Consolidation, Merger and Sale of Assets

The indenture will provide that we shall not consolidate with or merge with or into, or sell, convey, transfer or lease all or substantially all of our properties and assets to, another person, unless (i) the resulting, surviving or transferee person (if not us) is a corporation organized and existing under the laws of the United States of America, any State thereof or the District of Columbia, and such corporation (if not us) expressly assumes by supplemental indenture all of our obligations under the notes and the indenture; and (ii) immediately after giving effect to such transaction, no default or event of default has occurred and is continuing under the indenture. Upon any such consolidation, merger or sale, conveyance, transfer or lease, the resulting, surviving or transferee person (if not us) shall succeed to, and may exercise every right and power of, ours under the indenture, and we shall be discharged from our obligations under the notes and the indenture except in the case of any such lease.

Although these types of transactions will be permitted under the indenture, certain of the foregoing transactions could constitute a fundamental change permitting each holder to require us to repurchase the notes of such holder as described above.

This “—Consolidation, Merger and Sale of Assets” section replaces the section of the accompanying prospectus under the heading “Description of Debt Securities—Consolidation, Merger or Sale” in its entirety.

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Events of Default

Each of the following is an event of default with respect to the notes:

(1) default in any payment of interest on any note when due and payable and the default continues for a period of 30 days;

(2) default in the payment of principal of any note when due and payable at its stated maturity, upon optional redemption, upon any required repurchase, upon declaration of acceleration or otherwise;

(3) our failure to comply with our obligation to convert the notes in accordance with the indenture upon exercise of a holder’s conversion right and such failure continues for five (5) business days;

(4) our failure to give a fundamental change notice as described under “—Fundamental Change Permits Holders to Require Us to Repurchase Notes,” a notice of a make-whole fundamental change as described under “—Increase in Conversion Rate upon Conversion upon a Make-whole Fundamental Change or Notice of Redemption” or notice of a specified corporate transaction as described under “—Conversion Rights —Conversion upon Specified Corporate Events,” in each case when due and, except with respect to any notice of a specified corporate transaction as described under “—Conversion Rights —Conversion upon Specified Corporate Events—Certain Distributions,” such failure continues for five (5) business days;

(5) our failure to comply with our obligations under “—Consolidation, Merger and Sale of Assets”;

(6) our failure for 60 days after written notice from the trustee or the holders of at least 25% in principal amount of the notes then outstanding has been received to comply with any of our other agreements contained in the notes or indenture;

(7) default by us or any of our subsidiaries with respect to any mortgage, agreement or other instrument under which there may be outstanding, or by which there may be secured or evidenced, any indebtedness for money borrowed in excess of $10 million (or its foreign currency equivalent) in the aggregate of us and/or any such subsidiary, whether such indebtedness now exists or shall hereafter be created (i) resulting in such indebtedness becoming or being declared due and payable prior to its stated maturity date or (ii) constituting a failure to pay the principal or interest of any such debt when due and payable (after the expiration of all applicable grace periods) at its stated maturity, upon required repurchase, upon declaration of acceleration or otherwise, and in the cases of clauses (i) and (ii), such acceleration shall not have been rescinded or annulled or such failure to pay or default shall not have been cured or waived, or such indebtedness is not paid or discharged, as the case may be, within 30 days after written notice to us by the trustee or to us and the trustee by holders of at least 25% in aggregate principal amount of notes then outstanding in accordance with the indenture;

(8) certain events of bankruptcy, insolvency, or reorganization of us or any of our significant subsidiaries; or

(9) a final judgment or judgments for the payment of $10 million (or its foreign currency equivalent) or more (excluding any amounts covered by insurance) in the aggregate rendered against us or any of our subsidiaries, which judgment is not discharged, bonded, paid, waived or stayed within 60 days after (i) the date on which the right to appeal thereof has expired if no such appeal has commenced, or (ii) the date on which all rights to appeal have been extinguished.

A “significant subsidiary,” for purposes of clause (8) above, is a subsidiary that is a “significant subsidiary”, as defined in Article 1, Rule 1-02 of Regulation S-X promulgated by the SEC provided that, in the case of a subsidiary that meets the criteria of clause (3) of the definition thereof but not clause (1) or (2) thereof, such subsidiary shall not be deemed to be a significant subsidiary unless the subsidiary’s income from continuing operations before income taxes, extraordinary items and cumulative effect of a change in accounting principle exclusive of amounts attributable to any noncontrolling interests for the last completed fiscal year prior to the date of such determination exceeds $10 million.;

If an event of default occurs and is continuing, the trustee by notice to us, or the holders of at least 25% in principal amount of the outstanding notes by notice to us and the trustee, may, and the trustee at the request of

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such holders shall, declare 100% of the principal of and accrued and unpaid interest, if any, on all outstanding notes to be due and payable. In case of certain events of bankruptcy, insolvency or reorganization, involving us, 100% of the principal of and accrued and unpaid interest on the notes will automatically become due and payable. Upon such a declaration of acceleration, such principal and accrued and unpaid interest, if any, will be due and payable immediately.

Notwithstanding the foregoing and notwithstanding the remedies afforded to the holders of the notes upon the occurrence and continuation of an event of default as set forth under “Description of Debt Securities—Events of Default under the Indenture” in the accompanying prospectus, the indenture will provide that, to the extent we elect, the sole remedy for an event of default under the indenture relating to (i) our failure to file with the trustee pursuant to Section 314(a)(1) of the Trust Indenture Act any documents or reports that we are required to file with the SEC pursuant to Section 13 or 15(d) of the Exchange Act or (ii) our failure to comply with our obligations as set forth under “—Reports” below, will after the occurrence of such an event of default consist exclusively of the right to receive additional interest on the notes at a rate equal to 0.25% per annum of the principal amount of the notes outstanding for each day during the first 180 days after the occurrence of such an event of default and 0.50% per annum of the principal amount of the notes outstanding from the 181st day to, and including, the 365th day following the occurrence of such an event of default.

If we so elect, such additional interest will be payable in the same manner and on the same dates as the stated interest payable on the notes. On the 366th day after such event of default (if the event of default relating to the reporting obligations is not cured or waived prior to such 366th day), the notes will be subject to acceleration as provided above. The provisions of the indenture described in this paragraph will not affect the rights of holders of notes in the event of the occurrence of any other event of default. In the event we do not elect to pay the additional interest following an event of default in accordance with this paragraph or we elected to make such payment but do not pay the additional interest when due, the notes will be immediately subject to acceleration as provided above.

In order to elect to pay the additional interest as the sole remedy during the first 365 days after the occurrence of an event of default relating to the failure to comply with the reporting obligations in accordance with the immediately preceding paragraph, we must notify all holders of notes, the trustee and the paying agent of such election prior to the beginning of such 365-day period. Upon our failure to timely give such notice, the notes will be immediately subject to acceleration as provided above.

If any portion of the amount payable on the notes upon acceleration is considered by a court to be unearned interest (through the allocation of the value of the instrument to the embedded warrant or otherwise), the court could disallow recovery of any such portion.

The holders of a majority in principal amount of the outstanding notes may waive all past defaults (except with respect to nonpayment of principal or interest or with respect to the failure to deliver the consideration due upon conversion) and rescind any such acceleration with respect to the notes and its consequences if (i) rescission would not conflict with any judgment or decree of a court of competent jurisdiction and (ii) all existing events of default, other than the nonpayment of the principal of and interest on the notes that have become due solely by such declaration of acceleration, have been cured or waived.

Each holder shall have the right to receive payment or delivery, as the case may be, of:

its notes, on or after the respective due dates expressed or provided for in the indenture, or to institute suit for the enforcement of any such payment or delivery, as the case may be.

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Subject to the provisions of the indenture relating to the duties of the trustee, if an event of default occurs and is continuing, the trustee will be under no obligation to exercise any of the rights or powers under the indenture at the request or direction of any of the holders unless such holders have offered to the trustee indemnity or security reasonably satisfactory to it against any loss, liability or expense. Except to enforce the right to receive payment of principal or interest when due, or the right to receive payment or delivery of the consideration due upon conversion, no holder may pursue any remedy with respect to the indenture or the notes unless:

(1) such holder has previously given the trustee written notice that an event of default is continuing;

(2) holders of at least 25% in principal amount of the outstanding notes have requested the trustee to pursue the remedy;

(3) such holders have offered the trustee security or indemnity reasonably satisfactory to it against any loss, liability or expense;

(4) the trustee has not complied with such request within 60 days after the receipt of the request and the offer of such security or indemnity; and

(5) the holders of a majority in principal amount of the outstanding notes have not given the trustee a direction that, in the opinion of the trustee, is inconsistent with such request within such 60-day period.

Subject to certain restrictions, the holders of a majority in principal amount of the outstanding notes are given the right to direct the time, method and place of conducting any proceeding for any remedy available to the trustee or of exercising any trust or power conferred on the trustee.

The indenture will provide that in the event an event of default has occurred and is continuing, the trustee will be required in the exercise of its powers to use the degree of care that a prudent person would use in the conduct of its own affairs. The trustee, however, may refuse to follow any direction that conflicts with law or the indenture or that the trustee determines is unduly prejudicial to the rights of any other holder or that would involve the trustee in personal liability. Prior to taking any action under the indenture, the trustee will be entitled to indemnification reasonably satisfactory to it against any loss, liability or expense caused by taking or not taking such action.

The indenture will provide that if a default occurs and is continuing and is actually known to a responsible officer of the trustee, the trustee must deliver to each holder notice of the default within 90 days after it occurs. Except in the case of a default in the payment of principal of or interest on any note or a default in the payment or delivery of the consideration due upon conversion, the trustee may withhold notice if it in good faith determines that withholding notice is in the interests of the holders. In addition, we are required to deliver to the trustee, within 120 days after the end of each fiscal year, a certificate indicating whether the signers thereof know of any event of default under the indenture that occurred during the previous year. We are also required to deliver to the trustee, within 30 days after obtaining knowledge of the occurrence thereof, written notice of any events which would constitute certain events of defaults, their status and what action we are taking or proposing to take in respect thereof; provided that we are not required to deliver such notice if such event of default has been cured.

Payments of the redemption price, the fundamental change repurchase price, principal and interest that are not made when due will accrue interest per annum at the then-applicable interest rate from the required payment date.

This “—Events of Default” section replaces the section of the accompanying prospectus under the heading “Description of Debt Securities—Events of Default under the Indenture” in its entirety.

Modification and Amendment

Subject to certain exceptions, the indenture or the notes may be amended with the consent of the holders of at least a majority in principal amount of the notes then outstanding (including, without limitation, consents

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obtained in connection with a repurchase of, or tender or exchange offer for, notes) and, subject to certain exceptions, any past default or compliance with any provisions may be waived with the consent of the holders of a majority in principal amount of the notes then outstanding (including, without limitation, consents obtained in connection with a repurchase of, or tender or exchange offer for, notes). However, without the consent of each holder of an outstanding note affected, no amendment may, among other things:

(1) reduce the principal amount of notes whose holders must consent to an amendment;

(2) reduce the rate of or extend the stated time for payment of interest on any note;

(3) reduce the principal of or extend the stated maturity of any note;

(4) except as required by the indenture, make any change that adversely affects the conversion rights of any notes;

(5) reduce the redemption price, the fundamental change repurchase price of any note or amend or modify in any manner adverse to the holders of notes our obligation to make such payments, whether through an amendment or waiver of provisions in the covenants, definitions or otherwise;

(6) make any note payable in money, or at a place of payment, other than that stated in the note;

(7) change the ranking of the notes; or

(8) make any change in the amendment provisions that require each holder’s consent or in the waiver provisions.

Without the consent of any holder, we and the trustee may amend the indenture to:

(1) cure any ambiguity, omission, defect or inconsistency;

(2) provide for the assumption by a successor corporation of our obligations under the indenture;

(3) add guarantees with respect to the notes;

(4) secure the notes;

(5) add to our covenants or events of default for the benefit of the holders or surrender any right or power conferred upon us;

(6) make any change that does not adversely affect the rights of any holder in any material respect;

(7) in connection with any transaction described under “—Conversion Rights—Recapitalizations, Reclassifications and Changes of Our Common Stock” above, provide that the notes are convertible into reference property, subject to the provisions described under “—Conversion Rights—Settlement upon Conversion” above, and make certain related changes to the terms of the notes to the extent expressly required by the indenture;

(8) comply with any requirement of the SEC in connection with the qualification of the indenture under the Trust Indenture Act;

(9) conform the provisions of the indenture to the “Description of Notes” section in the preliminary prospectus supplement, as supplemented by the related pricing term sheet;

(10) comply with the rules of any applicable securities depositary, including DTC, so long as such amendment does not adversely affect the rights of any holder; or

(11) appoint a successor trustee with respect to the notes.

Holders do not need to approve the particular form of any proposed amendment. It will be sufficient if such holders approve the substance of the proposed amendment. After an amendment under the indenture becomes effective, we are required to deliver to the holders a notice briefly describing such amendment. However, the failure to give such notice to all the holders, or any defect in the notice, will not impair or affect the validity of the amendment.

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This “—Modification and Amendment” section replaces the section of the accompanying prospectus under the heading “Description of Debt Securities—Modification of Indenture; Waiver” in its entirety.

Discharge

We may satisfy and discharge our obligations under the indenture and the notes by delivering to the securities registrar for cancellation all outstanding notes or by depositing with the trustee or delivering to the holders, as applicable, after the notes have become due and payable, whether at maturity, at any redemption date, at any fundamental change repurchase date, upon conversion or otherwise, cash and/or shares of common stock, solely to satisfy outstanding conversions, as applicable, sufficient to pay all of the outstanding notes and paying all other sums payable under the indenture by us. Such discharge is subject to terms contained in the indenture.

This “—Discharge” section replaces the section of the accompanying prospectus under the heading “Description of Debt Securities—Discharge” in its entirety.

Calculations in Respect of Notes

Except as otherwise provided above, we will be responsible for making all calculations called for under the notes. These calculations include, but are not limited to, determinations of the stock price, the last reported sale prices of our common stock, the daily VWAPs, the daily conversion values, the daily settlement amounts, accrued interest payable on the notes and the conversion rate of the notes. We will make all these calculations in good faith and, absent manifest error, our calculations will be final and binding on holders of notes. We will provide a schedule of our calculations to each of the trustee and the conversion agent, and each of the trustee and the conversion agent is entitled to rely conclusively upon the accuracy of our calculations without independent verification. The trustee will forward our calculations to any holder of notes upon the request of that holder.

Reports

The indenture will provide that any annual or quarterly reports (on Form 10-K or Form 10-Q or any respective successor form) that we are required to file with the SEC pursuant to Section 13 or 15(d) of the Exchange Act (excluding any such information, documents or reports, or portions thereof, subject to confidential treatment and any correspondence with the SEC) must be filed by us with the trustee within 15 days after the same are required to be filed with the SEC (giving effect to any grace period provided by Rule 12b-25 under the Exchange Act (or any successor rule)). Documents filed by us with the SEC via the EDGAR system (or any successor system) will be deemed to be filed with the trustee as of the time such documents are filed via EDGAR, it being understood that the trustee shall have no responsibility to determine if any documents have been filed.

Trustee

U.S. Bank National Association is the trustee, security registrar, paying agent and conversion agent. U.S. Bank National Association, in each of its capacities, including without limitation as trustee, security registrar, paying agent and conversion agent, assumes no responsibility for the accuracy or completeness of the information concerning us or our affiliates or any other party contained in this document or the related documents or for any failure by us or any other party to disclose events that may have occurred and may affect the significance or accuracy of such information.

We maintain banking relationships in the ordinary course of business with the trustee and its affiliates.

Governing Law

The indenture will provide that it and the notes, and any claim, controversy or dispute arising under or related to the indenture or the notes, will be governed by and construed in accordance with the laws of the State of New York.

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This “—Governing Law” section replaces the section of the accompanying prospectus under the heading “Description of Debt Securities—Governing Law” in its entirety.

Book-entry, Settlement and Clearance

The Global Notes

The notes will be initially issued in the form of one or more registered notes in global form, without interest coupons (the “global notes”). Upon issuance, each of the global notes will be deposited with the trustee as custodian for DTC and registered in the name of Cede & Co., as nominee of DTC.

Ownership of beneficial interests in a global note will be limited to persons who have accounts with DTC (“DTC participants”) or persons who hold interests through DTC participants. We expect that under procedures established by DTC:

Beneficial interests in global notes may not be exchanged for notes in physical, certificated form except in the limited circumstances described below.

Book-entry Procedures for the Global Notes

All interests in the global notes will be subject to the operations and procedures of DTC and, therefore, you must allow for sufficient time in order to comply with these procedures if you wish to exercise any of your rights with respect to the notes. We provide the following summary of those operations and procedures solely for the convenience of investors. The operations and procedures of DTC are controlled by that settlement system and may be changed at any time. Neither we nor the underwriters are responsible for those operations or procedures.

DTC has advised us that it is:

DTC was created to hold securities for its participants and to facilitate the clearance and settlement of securities transactions between its participants through electronic book-entry changes to the accounts of its participants. DTC’s participants include securities brokers and dealers, including the underwriters; banks and trust companies; clearing corporations and other organizations. Indirect access to DTC’s system is also available to others such as banks, brokers, dealers and trust companies; these indirect participants clear through or maintain a custodial relationship with a DTC participant, either directly or indirectly. Investors who are not DTC participants may beneficially own securities held by or on behalf of DTC only through DTC participants or indirect participants in DTC.

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So long as DTC’s nominee is the registered owner of a global note, that nominee will be considered the sole owner or holder of the notes represented by that global note for all purposes under the indenture. Except as provided below, owners of beneficial interests in a global note:

As a result, each investor who owns a beneficial interest in a global note must rely on the procedures of DTC to exercise any rights of a holder of notes under the indenture (and, if the investor is not a participant or an indirect participant in DTC, on the procedures of the DTC participant through which the investor owns its interest).

Payments of principal and interest with respect to the notes represented by a global note will be made by the trustee to DTC’s nominee as the registered holder of the global note. Neither we nor the trustee will have any responsibility or liability for the payment of amounts to owners of beneficial interests in a global note, for any aspect of the records relating to or payments made on account of those interests by DTC, or for maintaining, supervising or reviewing any records of DTC relating to those interests.

Payments by participants and indirect participants in DTC to the owners of beneficial interests in a global note will be governed by standing instructions and customary industry practice and will be the responsibility of those participants or indirect participants and DTC.

Transfers between participants in DTC will be effected under DTC’s procedures and will be settled in same-day funds.

Certificated Notes

Notes in physical, certificated form will be issued and delivered to each person that DTC identifies as a beneficial owner of the related notes only if:

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DESCRIPTION OF CAPPED CALL TRANSACTIONS

In connection with the pricing of the notes, we expect to enter into capped call transactions with one or more of the underwriters and/or their respective affiliates or other financial institutions, which we refer to as the option counterparties. The capped call transactions will cover, subject to anti-dilution adjustments substantially similar to those applicable to the notes, the number of shares of our common stock underlying the notes.

We intend to use approximately $             million of the net proceeds from this offering to pay the cost of the capped call transactions. If the underwriters exercise their over-allotment option, we expect to enter into additional capped call transactions with the option counterparties.

The capped call transactions are expected generally to reduce the potential dilution upon conversion of the notes and/or offset any cash payments we are required to make in excess of the principal amount of converted notes, as the case may be, in the event that the market price per share of our common stock, as measured under the terms of the capped call transactions, is greater than the strike price of the capped call transactions, which initially corresponds to the conversion price of the notes and is subject to anti-dilution adjustments substantially similar to those applicable to the conversion rate of the notes. If, however, the market price per share of our common stock, as measured under the terms of the capped call transactions, exceeds the cap price of the capped call transactions, there would nevertheless be dilution and/or there would not be an offset of such potential cash payments, in each case, to the extent that such market price exceeds the cap price of the capped call transactions.

We will not be required to make any cash payments to the option counterparties or their respective affiliates upon the exercise of the options that are a part of the capped call transactions, but we will be entitled to receive from them a number of shares of our common stock, an amount of cash or a combination thereof generally based on the amount by which the market price per share of our common stock, as measured under the terms of the capped call transactions, is greater than the strike price of the capped call transactions during the relevant valuation period under the capped call transactions. However, if the market price per share of our common stock, as measured under the terms of the capped call transactions, exceeds the cap price of the capped call transactions during such valuation period, the number of shares of our common stock and/or the amount of cash we expect to receive upon exercise of the capped call transactions will be capped based on the amount by which the cap price exceeds the strike price of the capped call transactions.

The capped call transactions are separate transactions entered into by us with the option counterparties, are not part of the terms of the notes and will not change the holders’ rights under the notes. As a holder of the notes, you will not have any rights with respect to the capped call transactions.

For a discussion of the potential impact of any market or other activity by the option counterparties or their respective affiliates in connection with these capped call transactions, see “Underwriting—Capped Call Transactions” and “Risk Factors—Risks Related to the Notes—The capped call transactions may affect the value of the notes and our common stock.”

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CERTAIN MATERIAL U.S. FEDERAL INCOME TAX CONSIDERATIONS

The following is a summary of certain U.S. federal income tax considerations of the purchase, ownership and disposition of notes and the shares of common stock into which the notes may be converted. This summary is based upon provisions of the U.S. Internal Revenue Code of 1986, as amended, or the Code, applicable Treasury Regulations, administrative rulings and judicial decisions in effect as of the date hereof, any of which may subsequently be changed, possibly retroactively, so as to result in U.S. federal income tax consequences different from those discussed below. Except where noted, this summary deals only with a note or share of common stock held as a capital asset by a beneficial owner who purchased the note on original issuance at its “issue price” (the first price at which a substantial portion of the notes is sold to persons other than bond houses, brokers, or similar persons or organizations acting in the capacity of underwriters, placement agents or wholesalers) in this offering. This summary is general in nature and does not address all aspects of U.S. federal income taxes and does not address state, local, estate, gift or non-U.S. consequences. In addition, it does not deal with all tax consequences that may be relevant to holders in light of their personal circumstances or particular situations, such as:

If an entity or arrangement treated as a partnership holds notes or shares of common stock, the tax treatment of a partner will generally depend upon the status of the partner and the activities of the partnership. If you are a partner in a partnership holding the notes or shares of common stock, you should consult your tax advisor.

We have not sought, nor will we seek, a ruling from the Internal Revenue Service, or the IRS, with respect to the matters discussed below. There can be no assurance that the IRS will not take a different position concerning the tax consequences of the purchase, ownership or disposition of the notes or common stock or that any such position would not be sustained.

THIS SUMMARY OF CERTAIN U.S. FEDERAL INCOME TAX CONSIDERATIONS IS FOR GENERAL INFORMATION ONLY AND IS NOT TAX ADVICE. YOU SHOULD CONSULT YOUR TAX ADVISOR WITH RESPECT TO THE APPLICATION OF U.S. FEDERAL INCOME TAX LAWS TO YOUR PARTICULAR SITUATION AS WELL AS ANY TAX CONSEQUENCES OF THE PURCHASE, OWNERSHIP, AND DISPOSITION OF THE NOTES OR THE SHARES OF OUR COMMON STOCK INTO WHICH THE NOTES ARE CONVERTIBLE ARISING UNDER U.S. FEDERAL ESTATE OR GIFT TAX RULES OR UNDER THE LAWS OF ANY STATE, LOCAL, NON-U.S. OR ANY OTHER TAXING JURISDICTION OR UNDER ANY APPLICABLE TAX TREATY.

As used herein, the term “U.S. holder” means a beneficial owner of notes or shares of common stock received upon conversion of the notes that is, for U.S. federal income tax purposes:

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A “non-U.S. holder” is a beneficial owner (other than a partnership, or any entity treated as a partnership for U.S. federal income tax purposes) of notes or shares of common stock received upon conversion of the notes that is not a U.S. holder. Special rules may apply to certain non-U.S. holders such as individuals who are U.S. expatriates and certain non-U.S. holders that are subject to the Medicare net investment income tax. Consequently, non-U.S. holders should consult their tax advisors to determine the U.S. federal, state, local and other tax consequences that may be relevant to them.

Consequences to U.S. Holders

Interest

It is anticipated, and this discussion assumes, that the notes will be issued with less than a de minimis amount of original issue discount, if any (as determined under the Code). In such case, stated interest on a note will generally be taxable to a U.S. holder as ordinary income at the time it is paid or accrued in accordance with the U.S. holder’s usual method of accounting for tax purposes.

Additional Amounts

As described under the heading “Description of Notes—Events of Default,” we may pay additional interest on the notes in certain circumstances. We intend to take the position that the possibility of such payments or such conversion rate increase should not cause the notes to be treated as contingent payment debt instruments. This position is based in part on our assessment that the possibility, as of the date of issuance of the notes, that such additional amounts will be paid or that such increase in conversion rate will be made, is remote. Assuming such position is respected, any additional interest paid to a U.S. holder as described under “Description of Notes—Events of Default” would be taxable as additional ordinary income when received or accrued, in accordance with such U.S. holder’s method of accounting for U.S. federal income tax purposes.

Our position that the notes are not contingent payment debt instruments is binding on each U.S. holder unless such U.S. holder discloses its contrary position to the IRS in the manner required by applicable Treasury Regulations. Our position that the notes are not contingent payment debt instruments is not, however, binding on the IRS. If the IRS successfully challenged this position, and the notes were treated as contingent payment debt instruments because of the possibility of such payments or such increase, U.S. holders would, among other things, be required to accrue interest income at a higher rate than the stated interest rate on the notes and to treat any gain recognized on the sale or other disposition of a note (including any gain realized on the conversion of a note) as ordinary income rather than as capital gain. The remainder of this discussion assumes that the notes are not treated as contingent payment debt instruments.

Sale, Exchange, Repurchase, Retirement or Other Taxable Disposition of Notes

Except as provided below under “—Conversion of Notes” a U.S. holder will generally recognize gain or loss upon the sale, exchange, repurchase, retirement or other taxable disposition of a note, equal to the difference between the sum of the cash plus the fair market value of any other property received upon such disposition (excluding any amount attributable to accrued but unpaid interest, which will be treated as described above under “—Interest”) and such U.S. holder’s adjusted tax basis in the note. A U.S. holder’s adjusted tax basis in a note

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will generally be equal to the amount that the U.S. holder paid for the note, plus the amount, if any, included in income by the U.S. holder on an adjustment to the conversion rate of the notes, as described in “—Constructive Distributions” below. If, at the time of the sale, exchange, repurchase, retirement or other taxable disposition of the note, a U.S. holder held the note for more than one year, such gain or loss will be long-term capital gain or loss. Long-term capital gains recognized by certain non-corporate U.S. holders, including individuals, will generally be subject to a reduced rate of U.S. federal income tax. A U.S. holder’s ability to deduct capital losses may be limited.

Conversion of Notes

If a U.S. holder presents a note for conversion, a U.S. holder may receive solely cash, solely common stock or a combination of cash and common stock in exchange for notes, depending upon our chosen settlement method.

If a U.S. holder receives solely cash in exchange for notes upon conversion, the U.S. holder’s gain or loss will be determined in the same manner as if the U.S. holder disposed of the notes in a taxable disposition (as described above under “— Sale, Exchange, Repurchase, Retirement or Other Taxable Disposition of Notes”).

If a U.S. holder receives solely stock in exchange for a notes upon conversion, the U.S. holder generally will not recognize any income, gain or loss on the conversion, except with respect to cash received in lieu of a fractional share of common stock and the fair market value of any common stock attributable to accrued and unpaid interest. The U.S. holder’s aggregate tax basis in the common stock (including any fractional share for which cash is paid, but excluding shares attributable to accrued interest) will equal the U.S. holder’s tax basis in the note. The U.S. holder’s holding period in the common stock (other than shares attributable to accrued interest) will include the holding period in the note.

The U.S. federal income tax treatment of the conversion of a note into cash and common stock is uncertain, and U.S. holders should consult their tax advisors regarding the consequences of such a conversion. In general, the income tax treatment will depend on whether the conversion is treated as a recapitalization or alternatively as a conversion of a portion of the note for common stock and a taxable sale of a portion of the note for cash. The conversion can only be treated as a recapitalization if the notes are treated as “securities” for U.S. federal income tax purposes. An instrument is a “security” for these purposes if, based on all the facts and circumstances, the instrument constitutes a meaningful investment in the issuer of the instrument. Although there are a number of factors that may affect the determination of whether a debt instrument is a “security,” one of the most important factors is the original term of the instrument, or the length of time between the issuance of the instrument and its maturity. In general, instruments with an original term of more than ten years are likely to be treated as “securities,” and instruments with an original term of less than five years are less likely to be treated as “securities.” In addition, the convertibility of a debt instrument into stock of the issuer may argue in favor of “security” treatment because of the holder’s possible equity participation in the issuer. If recapitalization treatment applies, then a U.S. holder will recognize gain, but not loss, in an amount equal to the lesser of (i) the excess of the sum of the cash and the fair market value of the common stock received (other than amounts attributable to accrued interest, which will be treated as described above under “—Interest”) over the U.S. holder’s adjusted tax basis in the notes converted and (ii) the amount of cash received (other than cash received in lieu of a fractional share or cash attributable to accrued interest). Any gain recognized on conversion generally will be capital gain and will be long-term capital gain if, at the time of the conversion, the note has been held for more than one year.

The tax basis of the shares of common stock received upon a conversion that is treated as a recapitalization (including any fractional share deemed to be received by the U.S. holder but excluding common stock attributable to accrued interest) generally will equal the tax basis of the note that was converted, reduced by the amount of any cash received (other than cash received in lieu of a fractional share or cash attributable to accrued interest), and increased by the amount of gain, if any, recognized (other than with respect to a fractional share). A

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U.S. holder’s tax basis in a fractional share of our common stock will be determined by allocating such holder’s tax basis in the shares of our common stock, as determined in accordance with the previous sentence, between the shares of our common stock actually received and the fractional share of our common stock deemed received upon conversion, in accordance with their respective fair market values. A U.S. holder’s holding period for shares of common stock (other than common stock attributable to accrued interest) will include the period during which the U.S. holder held the notes.

If the conversion of a note into cash and common stock were not treated as a recapitalization, under an alternative characterization the cash payment received may be treated as proceeds from the sale of a portion of the note taxable in the manner described under “—Sale, Exchange, Repurchase, Retirement or Other Taxable Disposition of Notes” above, and the common stock received on such a conversion (other than common stock attributable to accrued interest) may be treated as received upon a conversion of the other portion of the note, which generally would not be taxable to a U.S. holder. In that case, the U.S. holder’s tax basis in the note would generally be allocated pro rata among the common stock received and the portion of the note that is treated as sold for cash, in accordance with their respective fair market values. The holding period for the common stock received in the conversion (other than common stock attributable to accrued interest) would include the holding period for the notes.

The fair market value of the shares of our common stock you receive with respect to accrued interest will be taxed as payment of interest and included in income as described above under “—Interest.” A U.S. holder’s tax basis in common stock attributable to accrued interest will equal its fair market value on the date of receipt and the holding period for such stock will commence on the day after the date of receipt.

Cash received in lieu of a fractional share of our common stock upon a conversion of a note should be treated as a payment in exchange for the fractional share of our common stock. Accordingly, the receipt of cash in lieu of a fractional share of our common stock should generally result in capital gain or loss, if any, measured by the difference between the cash received for the fractional share of our common stock and a U.S. holder’s tax basis allocable to such fractional share of our common stock.

As described in “Description of Notes —Conversion Rights —General,” our delivery of cash, common stock or a combination of cash and shares of common stock will be deemed to satisfy our obligation with respect to accrued and unpaid interest on the notes. We intend to take the position that upon a conversion of notes accrued and unpaid interest is paid first by any cash or common stock paid upon such conversion (other than cash paid in lieu of a fractional share).

Exchange in Lieu of Conversion

If a U.S. holder surrenders notes for conversion, we direct the notes to be offered to a financial institution for exchange in lieu of conversion, and the designated institution accepts the notes and delivers shares of our common stock (and cash in lieu of a fractional share of our common stock, if applicable) in exchange for the notes, the U.S. holder will be taxed on the transfer as a sale or exchange of the notes, as described above under “—Sale, Exchange, Repurchase, Retirement or Other Taxable Disposition of Notes.” In such case, a U.S. holder’s tax basis in the common stock received will equal the fair market value of the stock on the date of the exchange, and the holder’s holding period in the shares of common stock received will begin the day after the date of the exchange.

Possible Effect of the Change in Conversion Consideration

In the event we undergo certain of the events described under “Description of Notes—Recapitalizations, Reclassifications and Changes of Our Common Stock” or “Description of Notes—Consolidation, Merger and Sale of Assets,” the conversion rate and the related conversion consideration may be adjusted such that a U.S. holder would be entitled to convert its notes into shares, property or assets other than our common stock.

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Depending on the facts and circumstances at the time of such event, such adjustment may result in a deemed exchange of the outstanding notes, which may be a taxable event for U.S. federal income tax purposes. Whether or not such an adjustment results in a deemed exchange of the outstanding notes, a subsequent conversion of the notes might be treated as a fully taxable disposition of the notes if the property into which the notes are convertible is no longer stock of the notes’ obligor. Furthermore, depending on the circumstances, the U.S. federal income tax consequences of the exchange or conversion of the notes as well as the ownership of the notes and the shares may be different from the U.S. federal income tax consequences addressed in this disclosure. A U.S. holder should consult its tax advisor regarding the U.S. federal income tax consequences of such an adjustment.

Constructive Distributions

The conversion rate of the notes will be adjusted in certain circumstances. Adjustments (or failures to make adjustments) that have the effect of increasing a U.S. holder’s proportionate interest in our assets or earnings may in some circumstances result in a deemed distribution to a U.S. holder for U.S. federal income tax purposes even though no cash or property is received. Adjustments to the conversion rate made pursuant to a bona fide reasonable adjustment formula that has the effect of preventing the dilution of the interest of the holders of the notes, however, will generally not be considered to result in a deemed distribution to a U.S. holder. Certain of the possible conversion rate adjustments provided in the notes (including, without limitation, adjustments with respect to taxable dividends to holders of our common stock) will not qualify as being pursuant to a bona fide reasonable adjustment formula. If such adjustments are made, a U.S. holder will be deemed to have received a distribution even though the U.S. holder has not received any cash or property as a result of such adjustments. In addition, an adjustment to the conversion rate in connection with a make-whole fundamental change may be treated as a deemed distribution. Any deemed distributions will be taxable as a dividend, return of capital, or capital gain as described in “—Distributions” below. However, U.S. holders should consult with their own tax advisors as to whether a constructive dividend deemed paid to a non-corporate U.S. holder would be eligible for the preferential rates of U.S. federal income tax applicable in respect of certain dividends received. It is also unclear whether corporate U.S. holders would be entitled to claim the dividends received deduction with respect to any such constructive dividends. Because a constructive dividend deemed received by a U.S. holder would not give rise to any cash from which any applicable withholding could be satisfied, if backup withholding is paid on behalf of a U.S. holder (because such U.S. holder failed to establish an exemption from backup withholding), such backup withholding may be withheld from payments of cash and common stock payable on the notes (or, in certain circumstances, against any payments on the common stock). Generally, a U.S. holder’s adjusted tax basis in a note will be increased to the extent any such constructive distribution is treated as a dividend. U.S. holders should consult their tax advisors on the impact a constructive distribution may have on their holding period in the notes.

We are currently required to report the amount of any deemed distributions on our website or to the IRS and to holders of notes not exempt from reporting. On April 12, 2016, the IRS proposed regulations addressing the amount and timing of deemed distributions, obligations of withholding agents and filing and notice obligations of issuers. If adopted as proposed, the regulations would generally provide that (i) the amount of a deemed distribution is the excess of the fair market value of the right to acquire stock immediately after the conversion rate adjustment over the fair market value of the right to acquire stock without the adjustment (determined at the same time), (ii) the deemed distribution occurs at the earlier of the date the adjustment occurs under the terms of the note and the date of the actual distribution of cash or property that results in the deemed distribution and (iii) we are required to report the amount of any deemed distributions on our website or to the IRS and to all holders of notes (including holders of notes that would otherwise be exempt from reporting). The final regulations will be effective for deemed distributions occurring on or after the date of adoption, but holders of notes and withholding agents may rely on them prior to that date under certain circumstances.

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Distributions

Distributions, if any, made on our common stock generally will be included in a U.S. holder’s income as ordinary dividend income to the extent of our current or accumulated earnings and profits as determined for U.S. federal income tax purposes. However, with respect to dividends received by individuals, such dividends are generally taxed at the lower applicable long-term capital gains rates, provided certain holding period and other requirements for treatment of such dividends as “qualified dividend income” are satisfied. Distributions in excess of our current and accumulated earnings and profits will be treated as a return of capital to the extent of a U.S. holder’s tax basis in the common stock and thereafter as capital gain from the sale or exchange of such common stock. Dividends received by a corporation may be eligible for a dividends received deduction, subject to applicable limitations.

Sale or Other Taxable Disposition of Common Stock

Upon the sale or other taxable disposition of our common stock, a U.S. holder generally will recognize capital gain or loss equal to the difference between (i) the amount of cash and the fair market value of all other property received upon such disposition and (ii) the U.S. holder’s tax basis in the common stock. Such capital gain or loss will be long-term capital gain or loss if a U.S. holder’s holding period in the common stock is more than one year at the time of the taxable disposition. Long-term capital gains recognized by certain non-corporate U.S. holders (including individuals) will generally be subject to reduced rates of U.S. federal income tax. A U.S. holder’s ability to deduct capital losses may be limited.

Medicare Tax on Net Investment Income

Generally, a 3.8% Medicare contribution tax is imposed on the net investment income of certain individuals with a modified adjusted gross income of over $200,000 ($250,000 in the case of joint filers) and on the undistributed net investment income of certain estates and trusts. Interest and dividends received (or deemed to be received) by holders of the notes and our common stock and capital gains from the sale or other disposition of notes or common stock generally will constitute net investment income and be subject to the 3.8% tax. U.S. holders that are individuals, estates or trusts should consult their tax advisors regarding the applicability of the Medicare tax to them.

Information Reporting and Backup Withholding

Information reporting requirements generally will apply to payments of interest on the notes (including any additional interest that we may pay under circumstances described above under the heading “Description of Notes—Events of Default”) and dividends on shares of common stock (including constructive dividends deemed paid) and to the proceeds of a sale of a note or share of common stock paid to a U.S. holder unless the U.S. holder is an exempt recipient (such as a corporation). Backup withholding (currently at a 28% rate) will apply to those payments if the U.S. holder fails to provide its correct taxpayer identification number, or certification of exempt status, or if the U.S. holder is notified by the IRS that it has failed to report in full payments of interest and dividend income. Any amounts withheld under the backup withholding rules will be allowed as a refund or a credit against a U.S. holder’s U.S. federal income tax liability provided the required information is furnished timely to the IRS.

Consequences to Non-U.S. Holders

Payments of Interest

Subject to the discussions of backup withholding and withholding on foreign accounts below, U.S. federal income tax and the 30% U.S. federal withholding tax will not be applied to any payment of interest on a note to a non-U.S. holder provided that:

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Special certification rules apply to non-U.S. holders that are pass-through entities.

If a non-U.S. holder cannot satisfy the requirements described above, the gross amounts of interest paid will generally be subject to the 30% U.S. federal withholding tax, unless the non-U.S. holder provides the applicable withholding agent with a properly executed (1) IRS Form W-8BEN or IRS Form W-8BEN-E (or other applicable form) claiming an exemption from or reduction in withholding under the benefit of an applicable income tax treaty or (2) IRS Form W-8ECI (or other applicable form) stating that interest paid on the notes is not subject to withholding tax because it is effectively connected with the non-U.S. holder’s conduct of a trade or business in the United States and includible in the non-U.S. holder’s gross income. If a non-U.S. holder is engaged in a trade or business in the United States and interest on the notes is effectively connected with the conduct of that trade or business and, if required by an applicable income tax treaty, is attributable to a U.S. permanent establishment or a U.S. fixed base, then (although the non-U.S. holder will be exempt from the 30% withholding tax provided the certification requirements discussed above are satisfied) the non-U.S. holder will be subject to U.S. federal income tax on that interest on a net income basis generally in the same manner as if the non-U.S. holder were a U.S. holder. In addition, if a non-U.S. holder is a foreign corporation, it may be subject to a branch profits tax equal to 30% (or lesser rate under an applicable income tax treaty) of its earnings and profits for the taxable year, subject to adjustments, that are effectively connected with its conduct of a trade or business in the United States.

Dividends and Constructive Distributions

Any dividends paid to a non-U.S. holder with respect to the shares of common stock (and any deemed dividends resulting from certain adjustments, or failure to make adjustments, to the conversion rate, see “—Constructive Distributions” above) will be subject to withholding tax at a 30% rate or such lower rate as may be specified by an applicable income tax treaty. However, dividends that are effectively connected with a non-U.S. holder’s conduct of a trade or business within the United States and, if required by an applicable income tax treaty, are attributable to a U.S. permanent establishment or a U.S. fixed base, are not subject to the withholding tax, but instead are subject to U.S. federal income tax on a net income basis at applicable graduated individual or corporate rates. Certain certification requirements and disclosure requirements must be complied with in order for effectively connected income to be exempt from withholding. Any such effectively connected income received by a foreign corporation may, under certain circumstances, be subject to an additional branch profits tax at a 30% rate or such lower rate as may be specified by an applicable income tax treaty. Because a constructive dividend deemed received by a non-U.S. holder would not give rise to any cash from which any applicable withholding tax could be satisfied, if withholding taxes are paid on behalf of a non-U.S. holder, those withholding taxes may be withheld from payments of cash and common stock payable on the notes (or, in certain circumstances, against any payments on the common stock) or sales proceeds received by or other funds or assets of such holder.

A non-U.S. holder of shares of common stock that wishes to claim the benefit of an applicable income tax treaty rate is required to satisfy applicable certification and other requirements. If a non-U.S. holder is eligible for

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a reduced rate of U.S. withholding tax pursuant to an income tax treaty, it may obtain a refund of any excess amounts withheld by timely filing an appropriate claim for refund with the IRS.

Sale, Exchange, Repurchase, Retirement or Conversion of Notes or Shares of Common Stock

Subject to the discussions of backup withholding and withholding on foreign accounts below, any gain realized by a non-U.S. holder on the sale, exchange, repurchase, retirement or other taxable disposition of a note or common stock (including a conversion of a note into cash or a combination of cash and stock, or an exchange of notes in lieu of conversion) will not be subject to U.S. federal income tax unless:

If a non-U.S. holder’s gain is described in the first bullet point above, such holder will be subject to tax at regular graduated U.S. federal income tax rates on the net gain derived from the sale, exchange, repurchase, retirement, conversion or other taxable disposition of a note or common stock, generally in the same manner as if such holder were a U.S. holder. If a non-U.S. holder is a foreign corporation that recognizes gain described in the first bullet point above, such holder may also be subject to the branch profits tax equal to 30% (or such lower rate as may be prescribed under an applicable U.S. income tax treaty) of its effectively connected earnings and profits.

If a non-U.S. holder is described in the second bullet point above, such holder will be subject to a flat 30% tax on the gain recognized on the sale, exchange, repurchase, retirement, conversion or other taxable disposition of a note or common stock (which gain may be offset by certain U.S.-source capital losses), even though the holder is not considered a resident of the United States. Any amounts (including common stock) which a non-U.S. holder receives on a sale, exchange, repurchase, retirement, conversion or other taxable disposition of a note which are attributable to accrued interest will be taxable as interest and may be subject to the rules described above under “—Payments of Interest.”

In general, we would be a USRPHC if the fair market value of our U.S. real property interests equals or exceeds 50% of the sum of the fair market value of our worldwide real property interests plus our other assets used or held for use in a trade or business. We believe that we are not, and we do not anticipate becoming, a USRPHC for U.S. federal income tax purposes. However, there can be no assurance that we will not become a USRPHC in the future.

Information Reporting and Backup Withholding

Generally, we or an applicable withholding agent must report annually to the IRS and to non-U.S. holders the amount of interest (including any additional interest that we may be required to pay under circumstances described above under “Description of Notes—Events of Default”) and dividends paid to non-U.S. holders (including constructive dividends deemed paid) and the amount of tax, if any, withheld with respect to those payments. Copies of the information returns reporting such interest, dividends and withholding may also be made available to the tax authorities in the country in which a non-U.S. holder resides under the provisions of an

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applicable income tax treaty. In general, a non-U.S. holder will not be subject to backup withholding with respect to payments of interest or dividends that we make, provided the statement described above in the last bullet point under “—Payments of Interest” has been received (and we or an applicable withholding agent does not have actual knowledge or reason to know that the holder is a U.S. person, as defined under the Code, that is not an exempt recipient). In addition, a non-U.S. holder will be subject to information reporting and, depending on the circumstances, backup withholding with respect to payments of the proceeds of the sale of a note or share of common stock within the United States or conducted through certain U.S.-related financial intermediaries, unless the statement described above has been received (and the payer does not have actual knowledge or reason to know that a holder is a U.S. person, as defined under the Code, that is not an exempt recipient) or the non-U.S. holder otherwise establishes an exemption. Any amounts withheld under the backup withholding rules will be allowed as a refund or a credit against a non-U.S. holder’s U.S. federal income tax liability provided the required information is furnished timely to the IRS.

Withholding on Foreign Accounts

The Foreign Account Tax Compliance Act, or FATCA, imposes withholding at a 30% rate on certain types of “withholdable payments” (including interest or constructive dividends paid on, and the gross proceeds from the sale or other disposition of, certain debt instruments, and dividends paid on, and the gross proceeds from the sale or other disposition of, stock in a U.S. corporation) made to a “foreign financial institution” or to a “non-financial foreign entity” (all as defined in the Code) (whether such foreign financial institution or non-financial foreign entity is the beneficial owner or an intermediary), unless (1) the foreign financial institution undertakes certain diligence and reporting obligations, (2) the non-financial foreign entity either certifies it does not have any “substantial United States owners” (as defined in the Code) or furnishes identifying information regarding each substantial United States owner or (3) the foreign financial institution or non-financial foreign entity otherwise qualifies for an exemption from these rules. If the payee is a foreign financial institution and is subject to the diligence and reporting requirements in (1) above, it must enter into an agreement with the U.S. Department of the Treasury requiring, among other things, that it undertake to identify accounts held by certain U.S. persons or U.S.-owned foreign entities (as defined in applicable Treasury Regulations), annually report certain information about such accounts and withhold 30% on payments to noncompliant foreign financial institutions and certain other account holders. Foreign governments may enter into an agreement with the IRS to implement FATCA in a different manner.

Under recently issued Treasury Regulations and official guidance FATCA withholding currently applies to payments of interest on the notes and dividends on our shares and will apply to payments of gross proceeds from the sale or other disposition of the notes or our shares on or after January 1, 2019. Prospective investors should consult their tax advisors regarding the application of FATCA to the notes and our common stock.

Dividend Equivalents

Section 871(m) of the Code requires withholding (of up to 30%, depending on whether a treaty applies) on certain financial instruments to the extent that the payments or deemed payments on the financial instruments are treated as being contingent upon or determined by reference to U.S.-source dividends. Under Treasury Regulations promulgated under Section 871(m), Section 871(m) will apply to financial instruments issued in 2017 and 2018 only if they are “delta-one.” A “delta-one” instrument is one in which, the ratio of the change in the fair market value of the instrument to a small change in the fair market value of the property referenced by the instrument is equal to 1.00. We do not believe that the notes are delta-one instruments. Accordingly, non-U.S. holders of the notes should not be subject to tax under Section 871(m). However, it is possible that Section 871(m) withholding tax could apply to the notes under these rules in the future if a consolidation or merger results in a deemed taxable exchange and the notes are treated as newly issued after January 1, 2019. If withholding is required, we (or the applicable withholding agent) would be entitled to withhold such taxes without being required to pay any additional amounts with respect to amounts so withheld. Non-U.S. holders should consult with their tax advisors regarding the application of Section 871(m) and the regulations thereunder in respect of their acquisition and ownership of the notes.

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UNDERWRITING

Merrill Lynch, Pierce, Fenner & Smith Incorporated and Credit Suisse Securities (USA) LLC are acting as representatives of each of the underwriters named below. Subject to the terms and conditions set forth in an underwriting agreement among us and the underwriters, we have agreed to sell to the underwriters, and each of the underwriters has agreed, severally and not jointly, to purchase from us, the principal amount of notes set forth opposite its name below.

Subject to the terms and conditions set forth in the underwriting agreement, the underwriters have agreed, severally and not jointly, to purchase all of the notes sold under the underwriting agreement if any of these notes are purchased. If an underwriter defaults, the underwriting agreement provides that the purchase commitments of the nondefaulting underwriters may be increased or the underwriting agreement may be terminated.

We have agreed to indemnify the underwriters against certain liabilities, including liabilities under the Securities Act, or to contribute to payments the underwriters may be required to make in respect of those liabilities.

The underwriters are offering the notes, subject to prior sale, when, as and if issued to and accepted by them, subject to approval of legal matters by their counsel, including the validity of the notes, and other conditions contained in the underwriting agreement, such as the receipt by the underwriters of officer’s certificates and legal opinions. The underwriters reserve the right to withdraw, cancel or modify offers to the public and to reject orders in whole or in part.

Commissions and Discounts

The representatives have advised us that the underwriters propose initially to offer the notes at a price of     % of the principal amount of notes, plus accrued interest from the original issue date of the notes, if any, and to dealers at that price less a concession not in excess of     % of the principal amount of the notes, plus accrued interest from the original issue date of the notes, if any. After the initial offering, the public offering price, concession or any other term of the offering may be changed.

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The following table shows the public offering price, underwriting discount and proceeds before expenses to us. The information assumes either no exercise or full exercise by the underwriters of their option to purchase additional notes.

The expenses of the offering, not including the underwriting discount, are estimated at $600,000 and are payable by us.

Over-allotment option

We have granted an option to the underwriters to purchase up to an additional $15,000,000 principal amount of the notes at the public offering price, less the underwriting discount, solely to cover over-allotments, if any. The underwriters may exercise this option for 30 days from the date of this prospectus supplement. If the underwriters exercise this option, each will be obligated, subject to conditions contained in the underwriting agreement, to purchase an additional principal amount of the notes proportionate to that underwriter’s initial amount reflected in the above table.

New Issue of Notes

The notes are a new issue of securities with no established trading market. We do not intend to apply for listing of the notes on any national securities exchange or for inclusion of the notes on any automated dealer quotation system. We have been advised by the underwriters that they presently intend to make a market in the notes after completion of the offering. However, they are under no obligation to do so and may discontinue any market-making activities at any time without any notice. We cannot assure the liquidity of the trading market for the notes or that an active public market for the notes will develop. If an active public trading market for the notes does not develop, the market price and liquidity of the notes may be adversely affected. If the notes are traded, they may trade at a discount from their initial offering price, depending on prevailing interest rates, the market for similar securities, our operating performance and financial condition, general economic conditions and other factors.

Nasdaq Global Market Listing

Our common stock is listed on The NASDAQ Global Market under the symbol “EVBG.”

The transfer agent and registrar for our common stock is Computershare Trust Company, N.A. The transfer agent’s address is 250 Royall Street, Canton, Massachusetts 02021.

No Sales of Similar Securities

We and our executive officers and directors have agreed, with certain limited exceptions, that we and they will not, for a period of 60 days after the date of this prospectus supplement, without first obtaining the prior written consent of Merrill Lynch, Pierce, Fenner & Smith Incorporated and Credit Suisse Securities (USA) LLC, directly or indirectly

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This lock-up provision applies to our common stock and to securities convertible into or exchangeable or exercisable for or repayable with our common stock. It also applies to common stock owned now or acquired later by the person executing the agreement or for which the person executing the agreement later acquires the power of disposition.

Price Stabilization, Short Positions

In connection with the offering, the underwriters may purchase and sell the notes or shares of our common stock in the open market. These transactions may include short sales, purchases on the open market to cover positions created by short sales and stabilizing transactions. Short sales involve the sale by the underwriters of a greater principal amount of notes than they are required to purchase in the offering. “Covered” short sales are sales made in an amount not greater than the underwriters’ option to purchase additional notes described above. The underwriters may close out any covered short position by either exercising their option to purchase additional notes or purchasing notes in the open market. In determining the source of notes to close out the covered short position, the underwriters will consider, among other things, the price of notes available for purchase in the open market as compared to the price at which they may purchase notes through the option granted to them. “Naked” short sales are sales in excess of such option. The underwriters must close out any naked short position by purchasing notes in the open market. A naked short position is more likely to be created if the underwriters are concerned that there may be downward pressure on the price of the notes in the open market after pricing that could adversely affect investors who purchase in the offering. Stabilizing transactions consist of various bids for or purchases of notes or shares of our common stock made by the underwriters in the open market to peg, fix or maintain the price of the notes or our common stock prior to the completion of the offering.

Similar to other purchase transactions, the underwriters’ purchases to cover the syndicate short sales may have the effect of raising or maintaining the market price of the notes or preventing or retarding a decline in the market price of the notes. As a result, the price of the notes may be higher than the price that might otherwise exist in the open market.

Neither we nor any of the underwriters make any representation or prediction as to the direction or magnitude of any effect that the transactions described above may have on the price of the notes or our common stock. In addition, neither we nor any of the underwriters make any representation that the representatives will engage in these transactions or that these transactions, once commenced, will not be discontinued without notice.

Other Relationships

Some of the underwriters and their affiliates have engaged in, and may in the future engage in, investment banking and other commercial dealings in the ordinary course of business with us or our affiliates. They have received, or may in the future receive, customary fees and commissions for these transactions.

In addition, in the ordinary course of their business activities, the underwriters and their affiliates may make or hold a broad array of investments and actively trade debt and equity securities (or related derivative securities) and financial instruments (including bank loans) for their own account and for the accounts of their customers.

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Such investments and securities activities may involve securities and/or instruments of ours or our affiliates. The underwriters and their affiliates may also make investment recommendations and/or publish or express independent research views in respect of such securities or financial instruments and may hold, or recommend to clients that they acquire, long and/or short positions in such securities and instruments.

Electronic Distribution

In connection with the offering, certain of the underwriters or securities dealers may distribute this prospectus supplement and the accompanying prospectus by electronic means, such as e-mail.

European Economic Area

In relation to each member state of the European Economic Area, no offer of notes which are the subject of the offering has been, or will be made to the public in that Member State, other than under the following exemptions under the Prospectus Directive:

provided that no such offer of notes referred to in (a) to (c) above shall result in a requirement for the Company or any Representative to publish a prospectus pursuant to Article 3 of the Prospectus Directive, or supplement a prospectus pursuant to Article 16 of the Prospectus Directive.

Each person located in a Member State to whom any offer of notes is made or who receives any communication in respect of an offer of notes, or who initially acquires any notes will be deemed to have represented, warranted, acknowledged and agreed to and with each Representative and the Company that (1) it is a “qualified investor” within the meaning of the law in that Member State implementing Article 2(1)(e) of the Prospectus Directive; and (2) in the case of any notes acquired by it as a financial intermediary as that term is used in Article 3(2) of the Prospectus Directive, the notes acquired by it in the offer have not been acquired on behalf of, nor have they been acquired with a view to their offer or resale to, persons in any Member State other than qualified investors, as that term is defined in the Prospectus Directive, or in circumstances in which the prior consent of the Representatives has been given to the offer or resale; or where notes have been acquired by it on behalf of persons in any Member State other than qualified investors, the offer of those notes to it is not treated under the Prospectus Directive as having been made to such persons.

The Company, the Representatives and their respective affiliates will rely upon the truth and accuracy of the foregoing representations, acknowledgments and agreements.

This prospectus has been prepared on the basis that any offer of notes in any Member State will be made pursuant to an exemption under the Prospectus Directive from the requirement to publish a prospectus for offers of notes. Accordingly any person making or intending to make an offer in that Member State of notes which are the subject of the offering contemplated in this prospectus may only do so in circumstances in which no obligation arises for the Company or any of the Representatives to publish a prospectus pursuant to Article 3 of the Prospectus Directive in relation to such offer. Neither the Company nor the Representatives have authorized, nor do they authorize, the making of any offer of notes in circumstances in which an obligation arises for the Company or the Representatives to publish a prospectus for such offer.

For the purposes of this provision, the expression an “offer of notes to the public” in relation to any notes in any Member State means the communication in any form and by any means of sufficient information on the

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terms of the offer and the notes to be offered so as to enable an investor to decide to purchase or subscribe the notes, as the same may be varied in that Member State by any measure implementing the Prospectus Directive in that Member State, the expression “Prospectus Directive” means Directive 2003/71/EC (as amended) and includes any relevant implementing measure in each Member State.

The above selling restriction is in addition to any other selling restrictions set out below.

Notice to Prospective Investors in the United Kingdom

In addition, in the United Kingdom, this document is being distributed only to, and is directed only at, and any offer subsequently made may only be directed at persons who are “qualified investors” (as defined in the Prospectus Directive) (i) who have professional experience in matters relating to investments falling within Article 19 (5) of the Financial Services and Markets Act 2000 (Financial Promotion) Order 2005, as amended (the “Order”) and/or (ii) who are high net worth companies (or persons to whom it may otherwise be lawfully communicated) falling within Article 49(2)(a) to (d) of the Order (all such persons together being referred to as “relevant persons”). This document must not be acted on or relied on in the United Kingdom by persons who are not relevant persons. In the United Kingdom, any investment or investment activity to which this document relates is only available to, and will be engaged in with, relevant persons.

Notice to Prospective Investors in Switzerland

The notes may not be publicly offered in Switzerland and will not be listed on the SIX Swiss Exchange (“SIX”) or on any other stock exchange or regulated trading facility in Switzerland. This document has been prepared without regard to the disclosure standards for issuance prospectuses under art. 652a or art. 1156 of the Swiss Code of Obligations or the disclosure standards for listing prospectuses under art. 27 ff. of the SIX Listing Rules or the listing rules of any other stock exchange or regulated trading facility in Switzerland. Neither this document nor any other offering or marketing material relating to the notes or the offering may be publicly distributed or otherwise made publicly available in Switzerland.

Neither this document nor any other offering or marketing material relating to the offering, the Company, the notes have been or will be filed with or approved by any Swiss regulatory authority. In particular, this document will not be filed with, and the offer of the notes will not be supervised by, the Swiss Financial Market Supervisory Authority FINMA (FINMA), and the offer of the notes has not been and will not be authorized under the Swiss Federal Act on Collective Investment Schemes (“CISA”). The investor protection afforded to acquirers of interests in collective investment schemes under the CISA does not extend to acquirers of the notes.

Notice to Prospective Investors in the Dubai International Financial Centre

This prospectus supplement relates to an Exempt Offer in accordance with the Offered Securities Rules of the Dubai Financial Services Authority (“DFSA”). This prospectus supplement is intended for distribution only to persons of a type specified in the Offered Securities Rules of the DFSA. It must not be delivered to, or relied on by, any other person. The DFSA has no responsibility for reviewing or verifying any documents in connection with Exempt Offers. The DFSA has not approved this prospectus supplement nor taken steps to verify the information set forth herein and has no responsibility for the prospectus supplement. The notes to which this prospectus supplement relates may be illiquid and/or subject to restrictions on their resale. Prospective purchasers of the notes offered should conduct their own due diligence on the notes. If you do not understand the contents of this prospectus supplement you should consult an authorized financial advisor.

Notice to Prospective Investors in Australia

No placement document, prospectus, product disclosure statement or other disclosure document has been lodged with the Australian Securities and Investments Commission (“ASIC”), in relation to the offering. This

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prospectus does not constitute a prospectus, product disclosure statement or other disclosure document under the Corporations Act 2001 (the “Corporations Act”), and does not purport to include the information required for a prospectus, product disclosure statement or other disclosure document under the Corporations Act.

Any offer in Australia of the notes may only be made to persons (the “Exempt Investors”) who are “sophisticated investors” (within the meaning of section 708(8) of the Corporations Act), “professional investors” (within the meaning of section 708(11) of the Corporations Act) or otherwise pursuant to one or more exemptions contained in section 708 of the Corporations Act so that it is lawful to offer the notes without disclosure to investors under Chapter 6D of the Corporations Act.

The notes applied for by Exempt Investors in Australia must not be offered for sale in Australia in the period of 12 months after the date of allotment under the offering, except in circumstances where disclosure to investors under Chapter 6D of the Corporations Act would not be required pursuant to an exemption under section 708 of the Corporations Act or otherwise or where the offer is pursuant to a disclosure document which complies with Chapter 6D of the Corporations Act.

Further, any equity shares issued on conversion of the notes must not be offered for sale in Australia in the period of 12 months after the date of issue of those equity shares except in circumstances where disclosure to investors under Chapter 6D of the Corporations Act would not be required pursuant to an exemption under section 708 of the Corporations Act or otherwise or where the offer is pursuant to a disclosure document which complies with Chapter 6D of the Corporations Act. Any person acquiring notes or equity shares must observe such Australian on-sale restrictions.

This prospectus contains general information only and does not take account of the investment objectives, financial situation or particular needs of any particular person. It does not contain any securities recommendations or financial product advice. Before making an investment decision, investors need to consider whether the information in this prospectus is appropriate to their needs, objectives and circumstances, and, if necessary, seek expert advice on those matters.

Notice to Prospective Investors in Hong Kong

The securities have not been offered or sold and will not be offered or sold in Hong Kong, by means of any document, other than (a) to “professional investors” as defined in the Securities and Futures Ordinance (Cap. 571) of Hong Kong and any rules made under that Ordinance; or (b) in other circumstances which do not result in the document being a “prospectus” as defined in the Companies Ordinance (Cap. 32) of Hong Kong or which do not constitute an offer to the public within the meaning of that Ordinance. No advertisement, invitation or document relating to the securities has been or may be issued or has been or may be in the possession of any person for the purposes of issue, whether in Hong Kong or elsewhere, which is directed at, or the contents of which are likely to be accessed or read by, the public of Hong Kong (except if permitted to do so under the securities laws of Hong Kong) other than with respect to securities which are or are intended to be disposed of only to persons outside Hong Kong or only to “professional investors” as defined in the Securities and Futures Ordinance and any rules made under that Ordinance.

Notice to Prospective Investors in Singapore

This prospectus has not been registered as a prospectus with the Monetary Authority of Singapore. Accordingly, this prospectus and any other document or material in connection with the offer or sale, or invitation for subscription or purchase, of Non-CIS Securities may not be circulated or distributed, nor may the Non-CIS Securities be offered or sold, or be made the subject of an invitation for subscription or purchase, whether directly or indirectly, to persons in Singapore other than (i) to an institutional investor under Section 274 of the Securities and Futures Act, Chapter 289 of Singapore (the “SFA”), (ii) to a relevant person pursuant to Section 275(1), or any person pursuant to Section 275(1A), and in accordance with the conditions specified in

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Section 275, of the SFA, or (iii) otherwise pursuant to, and in accordance with the conditions of, any other applicable provision of the SFA.

Where the Non-CIS Securities are subscribed or purchased under Section 275 of the SFA by a relevant person which is:

securities (as defined in Section 239(1) of the SFA) of that corporation or the beneficiaries’ rights and interest (howsoever described) in that trust shall not be transferred within six months after that corporation or that trust has acquired the Non-CIS Securities pursuant to an offer made under Section 275 of the SFA except:

Notice to Prospective Investors in Canada

The securities may be sold only to purchasers purchasing, or deemed to be purchasing, as principal that are accredited investors, as defined in National Instrument 45-106 Prospectus Exemptions or subsection 73.3(1) of the Securities Act (Ontario), and are permitted clients, as defined in National Instrument 31-103 Registration Requirements, Exemptions and Ongoing Registrant Obligations. Any resale of the securities must be made in accordance with an exemption from, or in a transaction not subject to, the prospectus requirements of applicable securities laws.

Securities legislation in certain provinces or territories of Canada may provide a purchaser with remedies for rescission or damages if this prospectus (including any amendment thereto) contains a misrepresentation, provided that the remedies for rescission or damages are exercised by the purchaser within the time limit prescribed by the securities legislation of the purchaser’s province or territory. The purchaser should refer to any applicable provisions of the securities legislation of the purchaser’s province or territory for particulars of these rights or consult with a legal advisor.

Pursuant to section 3A.3 (or, in the case of securities issued or guaranteed by the government of a non-Canadian jurisdiction, section 3A.4) of National Instrument 33-105 Underwriting Conflicts (NI 33-105), the underwriters are not required to comply with the disclosure requirements of NI 33-105 regarding underwriter conflicts of interest in connection with this offering.

Capped Call Transactions

In connection with the pricing of the notes, we expect to enter into capped call transactions with one or more of the underwriters and/or their respective affiliates or other financial institutions, which we refer to as the option counterparties. The capped call transactions are expected generally to reduce the potential dilution to our common stock upon conversion of the notes and/or offset any cash payments we are required to make in excess of the principal amount of converted notes, as the case may be, with such reduction and/or offset subject to a cap.

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We intend to use approximately $             million of the net proceeds from this offering to pay the cost of the capped call transactions. If the underwriters exercise their over-allotment option, we expect to enter into additional capped call transactions with the option counterparties.

In connection with establishing their initial hedges of the capped call transactions, the option counterparties or their respective affiliates expect to enter into derivative transactions with respect to our common stock concurrently with or shortly after the pricing of the notes. This activity could increase (or reduce the size of any decrease in) the market price of our common stock or the notes at that time.

In addition, the option counterparties or their respective affiliates may modify their hedge positions by entering into or unwinding derivatives with respect to our common stock and/or purchasing or selling our common stock or other securities of ours in secondary market transactions following the pricing of the notes and prior to the maturity of the notes (and are likely to do so during any observation period related to a conversion of notes). This activity could also cause or avoid an increase or a decrease in the market price of our common stock or the notes, which could affect your ability to convert the notes and, to the extent the activity occurs during any observation period related to a conversion of notes, it could affect the number of shares and value of the consideration that you will receive upon conversion of the notes.

For a discussion of the potential impact of any market or other activity by the option counterparties or their respective affiliates in connection with the capped call transactions, see “Risk Factors—Risks Related to the Notes—The capped call transactions may affect the value of the notes and our common stock.”

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LEGAL MATTERS

Certain legal matters relating to the issuance of the notes offered by this prospectus supplement will be passed upon for us by Cooley LLP, Boston, Massachusetts. Goodwin Procter LLP, Boston, Massachusetts, and Davis Polk & Wardwell LLP, New York, New York, are counsel to the underwriters in connection with this offering.

EXPERTS

The consolidated financial statements of Everbridge, Inc. and subsidiaries as of December 31, 2016 and 2015, and for each of the years in the three-year period ended December 31, 2016, have been incorporated by reference herein and in the registration statement in reliance upon the report of KPMG LLP, independent registered public accounting firm, incorporated by reference herein, and upon the authority of said firm as experts in accounting and auditing.

WHERE YOU CAN FIND MORE INFORMATION

We are subject to the information requirements of the Exchange Act and, in accordance therewith, file annual, quarterly and special reports, proxy statements and other information with the SEC. You may read and copy any document we file at the SEC’s Public Reference Room at 100 F Street, N.E., Washington, D.C. 20549. You may call the SEC at 1-800-SEC-0330 for further information on the operation of the Public Reference Room. These documents also may be accessed through the SEC’s electronic data gathering, analysis and retrieval system, or EDGAR, via electronic means, including the SEC’s home page on the Internet (www.sec.gov).

This prospectus supplement and the accompanying prospectus are part of a registration statement on Form S-3 we filed with the SEC under the Securities Act and do not contain all the information set forth in the registration statement. Whenever a reference is made in this prospectus supplement or the accompanying prospectus to any of our contracts, agreements or other documents, the reference may not be complete and you should refer to the exhibits that are a part of the registration statement or the exhibits to the reports or other documents incorporated by reference into this prospectus supplement or the accompanying prospectus for a copy of such contract, agreement or other document.

INCORPORATION OF CERTAIN INFORMATION BY REFERENCE

The SEC allows us to “incorporate by reference” the information and reports we file with it, which means that we can disclose important information to you by referring you to these documents. The information incorporated by reference is an important part of this prospectus supplement and the accompanying prospectus, and information that we file later with the SEC will automatically update and supersede the information already incorporated by reference. We are incorporating by reference the documents listed below, which we have already filed with the SEC, and any future filings we make with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act (other than Current Reports or portions furnished under Items 2.02 or 7.01 of Form 8-K), including all filings made after the date of this prospectus supplement and prior to the termination of the offering of the common stock covered by this prospectus supplement:

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Upon request, we will provide, without charge, to each person, including any beneficial owner, to whom a copy of this prospectus supplement and the accompanying prospectus is delivered, a copy of the documents incorporated by reference into this prospectus supplement and accompanying prospectus. You may request a copy of these filings, and any exhibits we have specifically incorporated by reference as an exhibit in this prospectus supplement or the accompanying prospectus, at no cost by writing or telephoning us at the following address: Everbridge, Inc., 25 Corporate Drive, Suite 400, Burlington, Massachusetts 01803 Attention: General Counsel, or by telephone request to (818) 230-9700.

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PROSPECTUS

$300,000,000

Common Stock

Preferred Stock

Debt Securities

Warrants

and

1,000,000 Shares

Common Stock

Offered by Selling Stockholders

From time to time, we may offer and sell up to an aggregate amount of $300,000,000 of any combination of the securities described in this prospectus in one or more offerings. We may also offer securities as may be issuable upon conversion, redemption, repurchase, exchange or exercise of any securities registered hereunder, including any applicable antidilution provisions. In addition, selling stockholders to be named in the applicable prospectus supplement may offer and sell up to an aggregate of 1,000,000 shares of our common stock, from time to time, on the terms described in this prospectus or in an applicable prospectus supplement. We will not receive any of the proceeds from the sale of the shares offered by the selling stockholders hereunder. To the extent that any selling stockholder resells any securities, the selling stockholder may be required to provide you with this prospectus and a prospectus supplement identifying and containing specific information about the selling stockholder and the terms of the securities being offered. We and the selling stockholders may sell the securities to or through underwriters and also to other purchasers or through agents. The names of any underwriters or agents, and any fees, conversions, or discount arrangements will be set forth in the applicable prospectus supplement accompanying this prospectus.

We will provide the specific terms of these offerings in one or more supplements to this prospectus. We may also authorize one or more free writing prospectuses to be provided to you in connection with these offerings. The prospectus supplement and any related free writing prospectus may also add, update or change information contained in this prospectus. You should carefully read this prospectus, the applicable prospectus supplement and any related free writing prospectus, as well as any documents incorporated by reference, before buying any of the securities being offered. This prospectus may not be used to consummate a sale of securities unless it is accompanied by the applicable prospectus supplement.

Our common stock is listed on the NASDAQ Global Market under the symbol “EVBG.” On September 29, 2017, the closing price for our common stock, as reported on the NASDAQ Global Market, was $26.42 per share.

We are an “emerging growth company” as defined under the federal securities laws and, as such, have elected to comply with certain reduced public company reporting requirements.

Investing in our securities involves a high degree of risk. You should review carefully the risks and uncertainties described under the heading “Risk Factors” contained in this prospectus beginning on page 8 and any applicable prospectus supplement and in any free writing prospectuses we have authorized for use in connection with a specific offering, and under similar headings in the other documents that are incorporated by reference into this prospectus.

Neither the Securities and Exchange Commission nor any state securities commission has approved or disapproved of these securities or determined if this prospectus is truthful or complete. Any representation to the contrary is a criminal offense.

The date of this prospectus is October 13, 2017.

TABLE OF CONTENTS

ABOUT THIS PROSPECTUS

This prospectus is part of a registration statement that we filed with the Securities and Exchange Commission, or the SEC, using a “shelf” registration process. Under this shelf registration process, we may, from time to time, offer and sell, either individually or in combination, in one or more offerings, up to a total dollar amount of $300,000,000 of shares of our common stock and preferred stock, various series of debt securities and/or warrants to purchase any of such securities. In addition, under this shelf process, the selling stockholders to be named in a supplement to this prospectus may, from time to time, offer and sell up to 1,000,000 shares of our common stock, as described in this prospectus and such prospectus supplement, in one or more offerings.

This prospectus provides you with a general description of the securities we or the selling stockholders may offer. Each time we or the selling stockholders offer securities under this prospectus, we will provide a prospectus supplement that will contain more specific information about the terms of that offering. We may also authorize one or more free writing prospectuses to be provided to you that may contain material information relating to these offerings. The prospectus supplement and any related free writing prospectus that we may authorize to be provided to you may also add, update or change any of the information contained in this prospectus or in the documents that we have incorporated by reference into this prospectus. We urge you to read carefully this prospectus, any applicable prospectus supplement and any related free writing prospectuses we have authorized for use in connection with a specific offering, together with the information incorporated herein by reference as described under the heading “Incorporation of Certain Information By Reference,” before buying any of the securities being offered.

This prospectus may not be used to consummate a sale of securities unless it is accompanied by a prospectus supplement.

You should rely only on the information contained in, or incorporated by reference into, this prospectus and any applicable prospectus supplement, along with the information contained in any free writing prospectuses we have authorized for use in connection with a specific offering. Neither we nor any selling stockholder have authorized anyone to provide you with information in addition to or different from that contained in this prospectus, any applicable prospectus supplement and any related free writing prospectus. We take no responsibility for, and can provide no assurances as to the reliability of, any information not contained in this prospectus, any applicable prospectus supplement or any related free writing prospectus that we or a selling stockholder may authorize to be provided to you. This prospectus is an offer to sell only the securities offered hereby, but only under circumstances and in jurisdictions where it is lawful to do so. You should assume that the information in this prospectus, any applicable prospectus supplement or any related free writing prospectus is accurate only as of the date on the front of the document and that any information incorporated by reference is accurate only as of the date of the document incorporated by reference, regardless of the time of delivery of this prospectus, any applicable prospectus supplement or any related free writing prospectus, or any sale of a security. Our business, financial condition, results of operations and prospects may have changed since those dates.

Unless the context otherwise indicates, references in this prospectus to “Everbridge,” “we,” “our,” “us” and “the Company” refer, collectively, to Everbridge, Inc., a Delaware corporation. Our principal executive offices are located at 25 Corporate Drive, Suite 400, Burlington, Massachusetts 01803 and our telephone number is (818) 230-9700.

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RISK FACTORS

Investing in our securities involves a high degree of risk. Before deciding whether to invest in our securities, you should carefully consider the risks described in this prospectus and any applicable prospectus supplement (including the documents incorporated by reference herein and therein) and any related free writing prospectus, as well as other information we include or incorporate by reference into this prospectus and any applicable prospectus supplement, before making an investment decision. Our business, financial condition or results of operations could be materially adversely affected by any of these risks. The trading price of our securities could decline due to the occurrence of any of these risks, and you may lose all or part of your investment. This prospectus and the documents incorporated herein by reference also contain forward-looking statements that involve risks and uncertainties. Actual results could differ materially from those anticipated in these forward-looking statements as a result of certain factors, including the risks described above and in the documents incorporated herein by reference, including in (1) our most recent annual report on Form 10-K on file with the SEC, (2) our most recent quarterly report on Form 10-Q on file with the SEC and (3) as well as any amendments thereto reflected in subsequent filings with the SEC, all of which are incorporated by reference into this prospectus in their entirety, together with other information in this prospectus, the documents incorporated by reference and any free writing prospectus that we may authorize for use in connection with a specific offering.

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SPECIAL NOTE REGARDING FORWARD-LOOKING STATEMENTS

This prospectus, including the documents that we incorporate by reference, contains forward-looking statements within the meaning of Section 27A of the Securities Act of 1933, as amended, or the Securities Act, and Section 21E of the Securities Exchange Act of 1934, or the Exchange Act. Any statements about our expectations, beliefs, plans, objectives, assumptions or future events or performance are not historical facts and may be forward-looking. These statements are often, but are not always, made through the use of words or phrases such as “may,” “could,” “should,” “expects,” “intends,” “plans,” “anticipates,” “believes,” “estimates,” “predicts,” “projects,” “potential,” “continue,” and similar expressions, or the negative of these terms, or similar expressions. Accordingly, these statements involve estimates, assumptions and uncertainties which could cause actual results to differ materially from those expressed in them. Any forward-looking statements are qualified in their entirety by reference to the factors discussed throughout this prospectus, and in particular those factors referenced in the section “Risk Factors.”

This prospectus contains forward-looking statements that are based on our management’s belief and assumptions and on information currently available to our management. These statements relate to future events or our future financial performance, and involve known and unknown risks, uncertainties and other factors that may cause our actual results, levels of activity, performance or achievements to be materially different from any future results, levels of activity, performance or achievements expressed or implied by these forward-looking statements.

Except as required by law, we assume no obligation to update these forward-looking statements, or to update the reasons actual results could differ materially from those anticipated in these forward-looking statements, even if new information becomes available in the future.

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USE OF PROCEEDS

Except as described in any applicable prospectus supplement or in any related free writing prospectuses we may authorize for use in connection with a specific offering, we currently intend to use the net proceeds from the sale of the securities offered by us hereunder, if any, for working capital, capital expenditures and other general corporate purposes. In addition, we may use a portion of the proceeds for the acquisition of, or investment in, technologies, solutions or businesses that complement our business, although we have no present commitments or agreements to enter into any such acquisitions or investments. As of the date of this prospectus, we cannot specify with certainty all of the particular uses for the net proceeds to us from the sale of the securities offered by us hereunder. We will set forth in the applicable prospectus supplement or free writing prospectus our intended use for the net proceeds received from the sale of any securities sold pursuant to the prospectus supplement or free writing prospectus.

We will not receive any proceeds from the sale of shares of our common stock by any selling stockholder.

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DESCRIPTION OF CAPITAL STOCK

The following description of our capital stock, of certain provisions of our amended and restated certificate of incorporation and amended and restated by-laws, and of certain provisions of Delaware law, together with the additional information we include in any applicable prospectus supplement and in any related free writing prospectus, summarizes the material terms and provisions of our capital stock. The following description of our capital stock is a summary and does not purport to be complete and is subject to, and qualified in its entirety by reference to our amended and restated certificate of incorporation and our amended and restated by-laws, which are filed as exhibits to the registration statement of which this prospectus forms a part.

Authorized Capital Stock

Our authorized capital stock consists of 100,000,000 shares of common stock, par value $0.001 per share, and 10,000,000 shares of preferred stock, par value $0.001 per share, all of which are undesignated. As of September 29, 2017, we had 28,202,650 shares of common stock outstanding and no shares of preferred stock outstanding.

Common Stock

The holders of our common stock are entitled to one vote for each share held on all matters submitted to a vote of the stockholders. The holders of our common stock do not have any cumulative voting rights. Because of this, the holders of a majority of the shares of common stock entitled to vote in any election of directors can elect all of the directors standing for election, if they should so choose. Holders of our common stock are entitled to receive ratably any dividends declared by the board of directors out of funds legally available for that purpose, subject to any preferential dividend rights of any outstanding preferred stock. Our common stock has no preemptive rights, conversion rights or other subscription rights or redemption or sinking fund provisions.

In the event of our liquidation, dissolution or winding up, holders of our common stock will be entitled to share ratably in all assets remaining after payment of all debts and other liabilities and any liquidation preference of any outstanding preferred stock. All of our outstanding shares of common stock are, and the shares of common stock to be sold in this offering are, fully paid and nonassessable.

The rights, preferences and privileges of the holders of common stock are subject to, and may be adversely affected by, the rights of the holders of shares of any series of preferred stock that we may designate in the future.

Preferred Stock

Under our certificate of incorporation, our board of directors has the authority, without further action by our stockholders, to issue up to 10,000,000 shares of preferred stock in one or more series and to fix the rights, preferences, privileges and restrictions thereof. These rights, preferences and privileges could include dividend rights, conversion rights, voting rights, terms of redemption, liquidation preferences, sinking fund terms and the number of shares constituting, or the designation of, such series, any or all of which may be more favorable than the rights of our common stock. Our board of directors can, without stockholder approval but subject to the terms of the certificate of incorporation, issue preferred stock with voting and other rights that could adversely affect the voting power of the holders of our common stock and which could have certain anti-takeover effects. Before we may issue any series of preferred stock, our board of directors will be required to adopt resolutions creating and designating such series of preferred stock.

The following summary of terms of our preferred stock is not complete. You should refer to the provisions of our certificate of incorporation and bylaws and the resolutions containing the terms of each class or series of the preferred stock which have been or will be filed with the SEC at or prior to the time of issuance of such class or

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series of preferred stock and described in the applicable prospectus supplement. The applicable prospectus supplement may also state that any of the terms set forth herein are inapplicable to such series of preferred stock, provided that the information set forth in such prospectus supplement does not constitute material changes to the information herein such that it alters the nature of the offering or the securities offered.

We will fix the designations, voting powers, preferences and rights of the preferred stock of each series we issue under this prospectus, as well as the qualifications, limitations or restrictions thereof, in the certificate of designation relating to that series. We will file as an exhibit to the registration statement of which this prospectus is a part, or will incorporate by reference from reports that we file with the SEC, the form of any certificate of designation that describes the terms of the series of preferred stock we are offering. We will describe in the applicable prospectus supplement the terms of the series of preferred stock being offered, including, to the extent applicable:

If we issue shares of preferred stock under this prospectus, the shares will be validly issued, fully paid and non-assessable.

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The General Corporation Law of the State of Delaware, the state of our incorporation, provides that the holders of preferred stock will have the right to vote separately as a class on any proposal involving fundamental changes in the rights of holders of that preferred stock. This right is in addition to any voting rights that may be provided for in the applicable certificate of designation.

The issuance of our preferred stock could adversely affect the voting power of holders of common stock and the likelihood that such holders will receive dividend payments and payments upon our liquidation. In addition, the issuance of preferred stock could have the effect of delaying, deferring or preventing a change in control of our company or other corporate action.

Anti-Takeover Provisions of Our Certificate of Incorporation and By-laws and Delaware Law

Our certificate of incorporation and by-laws, as well as Section 203 of the Delaware General Corporation Law, include a number of provisions that may have the effect of delaying, deferring or preventing another party from acquiring control of us and encouraging persons considering unsolicited tender offers or other unilateral takeover proposals to negotiate with our board of directors rather than pursue non-negotiated takeover attempts. These provisions include the items described below.

Board composition and filling vacancies

Our certificate of incorporation provides for the division of our board of directors into three classes serving staggered three-year terms, with one class being elected each year. Our certificate of incorporation also provides that directors may be removed only for cause and then only by the affirmative vote of the holders of 66 2/3% or more of the shares then entitled to vote at an election of directors. Furthermore, the authorized number of directors number of directors may be changed only by resolution of the board of directors, and any vacancy on our board of directors, however occurring, including a vacancy resulting from an increase in the size of our board, may only be filled by the affirmative vote of a majority of our directors then in office, even if less than a quorum. The classification of directors, together with the limitations on removal of directors and treatment of vacancies, has the effect of making it more difficult for stockholders to change the composition of our board of directors.

No written consent of stockholders

Our certificate of incorporation provides that all stockholder actions are required to be taken by a vote of the stockholders at an annual or special meeting, and that stockholders may not take any action by written consent in lieu of a meeting. This limit may lengthen the amount of time required to take stockholder actions and would prevent the amendment of our by-laws or removal of directors by our stockholders without holding a meeting of stockholders.

Meetings of stockholders

Our certificate of incorporation and by-laws provide that only our chairman of the board, chief executive officer or a majority of the members of our board of directors then in office may call special meetings of stockholders and only those matters set forth in the notice of the special meeting may be considered or acted upon at a special meeting of stockholders. Our by-laws limit the business that may be conducted at an annual meeting of stockholders to those matters properly brought before the meeting.

Advance notice requirements

Our by-laws establish advance notice procedures with regard to stockholder proposals relating to the nomination of candidates for election as directors or new business to be brought before meetings of our stockholders. These procedures provide that notice of stockholder proposals must be timely given in writing to our corporate

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secretary prior to the meeting at which the action is to be taken. Generally, to be timely, notice must be received at our principal executive offices not less than 90 days nor more than 120 days prior to the first anniversary date of the annual meeting for the preceding year. Our by-laws specify the requirements as to form and content of all stockholders’ notices. These requirements may preclude stockholders from bringing matters before the stockholders at an annual or special meeting.

Amendment to certificate of incorporation and by-laws

Any amendment of our certificate of incorporation must first be approved by a majority of our board of directors, and if required by law or our certificate of incorporation, must thereafter be approved by a majority of the outstanding shares entitled to vote on the amendment and a majority of the outstanding shares of each class entitled to vote thereon as a class, except that the amendment of the provisions relating to stockholder action, board composition, limitation of liability, forum selection and the amendment of our by-laws or our certificate of incorporation must be approved by not less than 66 2/3% of the outstanding shares entitled to vote on the amendment. Our by-laws may be amended by the affirmative vote of a majority of the directors then in office, subject to any limitations set forth in the by-laws; and may also be amended by the affirmative vote of at least 66 2/3% of the outstanding shares entitled to vote on the amendment, voting together as a single class.

Undesignated preferred stock

Our certificate of incorporation provides for 10,000,000 authorized shares of preferred stock. The existence of authorized but unissued shares of preferred stock may enable our board of directors to discourage an attempt to obtain control of us by means of a merger, tender offer, proxy contest or otherwise. For example, if in the due exercise of its fiduciary obligations, our board of directors were to determine that a takeover proposal is not in the best interests of our stockholders, our board of directors could cause shares of preferred stock to be issued without stockholder approval in one or more private offerings or other transactions that might dilute the voting or other rights of the proposed acquirer or insurgent stockholder or stockholder group. In this regard, our certificate of incorporation grants our board of directors broad power to establish the rights and preferences of authorized and unissued shares of preferred stock. The issuance of shares of preferred stock could decrease the amount of earnings and assets available for distribution to holders of shares of common stock. The issuance may also adversely affect the rights and powers, including voting rights, of these holders and may have the effect of delaying, deterring or preventing a change in control of us.

Section 203 of the Delaware general corporation law

We are subject to the provisions of Section 203 of the Delaware General Corporation Law. In general, Section 203 prohibits a publicly held Delaware corporation from engaging in a “business combination” with an “interested stockholder” for a three-year period following the time that this stockholder becomes an interested stockholder, unless the business combination is approved in a prescribed manner. Under Section 203, a business combination between a corporation and an interested stockholder is prohibited unless it satisfies one of the following conditions:

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Section 203 defines a business combination to include:

In general, Section 203 defines an interested stockholder as any entity or person beneficially owning 15% or more of the outstanding voting stock of the corporation and any entity or person affiliated with or controlling or controlled by the entity or person.

Choice of Forum

Our certificate of incorporation provides that the Court of Chancery of the State of Delaware is the exclusive forum for any derivative action or proceeding brought on our behalf; any action asserting a breach of fiduciary duty owed by and of our directors, officers or employees to us or our stockholders; any action asserting a claim against us arising pursuant to the Delaware General Corporation Law, our certificate of incorporation or our by-laws; or any action asserting a claim against us that is governed by the internal affairs doctrine. Several lawsuits have been filed in Delaware challenging the enforceability of similar choice of forum provisions and it is possible that a court determines such provisions are not enforceable.

Registration Rights

Certain holders of shares of our common stock are entitled to certain rights with respect to registration of such shares under the Securities Act pursuant to the terms of an investors’ rights agreement. These shares are collectively referred to herein as registrable securities.

The investors’ rights agreement provides the holders of registrable securities with demand, piggyback and S-3 registration rights as described more fully below. As of December 31, 2016, an aggregate of 10,756,295 registrable securities were entitled to these registration rights. Subsequent to December 31, 2016, registration rights with respect to 5,109,764 of these securities were terminated when such securities were transferred. As of September 29, 2017, our affiliates held 3,735,767 registrable securities entitled to registration rights. The balance of the securities that may be entitled to registration rights are held by non-affiliates and therefore registration rights with respect to such securities may have terminated, without our knowledge, upon the disposition of such securities subsequent to December 31, 2016.

Demand Registration Rights

The holders of 20% of the registrable securities have the right to make up to two demands that we file a registration statement under the Securities Act covering at least 20% of the registrable securities then outstanding and with an anticipated aggregate offering price of greater than $10.0 million, net of underwriting discounts and commissions, subject to specified exceptions.

Piggyback Registration Rights

If we register any securities for public sale, the holders of our registrable securities then outstanding will each be entitled to notice of the registration and will have the right to include their shares in the registration statement.

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The underwriters of any underwritten offering will have the right to limit the number of shares having registration rights to be included in the registration statement, provided that the registration does not include shares of any other selling stockholder. If the registration does not include shares of any other selling stockholder, any or all of the registrable securities may be excluded from such registration.

Registration on Form S-3

If we are eligible to file a registration statement on Form S-3, the holders of our registrable securities have the right to demand that we file registration statements on Form S-3; provided, that the aggregate amount of securities to be sold under the registration statement is at least $3.0 million, net of underwriting discounts and commissions. We are not obligated to effect a demand for registration on Form S-3 by holders of our registrable securities more than twice during any 12-month period, and not more than four times in total. The right to have such shares registered on Form S-3 is further subject to other specified conditions and limitations.

Expenses of Registration

We will pay all expenses relating to any demand, piggyback or Form S-3 registration, other than underwriting discounts and commissions, subject to specified conditions and limitations.

Termination of Registration Rights

These registration rights will terminate on September 21, 2019.

Exchange Listing

Our common stock is listed on the NASDAQ Global Market under the symbol “EVBG.” On September 29, 2017, the closing price for our common stock was $26.42 per share. As of September 29, 2017, we had approximately 512 stockholders of record.

Transfer Agent and Registrar

The transfer agent and registrar for our common stock is Computershare Trust Company, N.A. The transfer agent’s address is 250 Royall Street, Canton, Massachusetts 02021.

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DESCRIPTION OF DEBT SECURITIES

We may issue debt securities from time to time, in one or more series, as either senior or subordinated debt or as senior or subordinated convertible debt. While the terms we have summarized below will apply generally to any debt securities that we may offer under this prospectus, we will describe the particular terms of any debt securities that we may offer in more detail in the applicable prospectus supplement. The terms of any debt securities offered under a prospectus supplement may differ from the terms described below. Unless the context requires otherwise, whenever we refer to the indenture, we also are referring to any supplemental indentures that specify the terms of a particular series of debt securities.

We will issue the debt securities under the indenture that we will enter into with the trustee named in the indenture. The indenture will be qualified under the Trust Indenture Act of 1939, as amended, or the Trust Indenture Act. We have filed the form of indenture as an exhibit to the registration statement of which this prospectus is a part, and supplemental indentures and forms of debt securities containing the terms of the debt securities being offered will be filed as exhibits to the registration statement of which this prospectus is a part or will be incorporated by reference from reports that we file with the SEC.

The following summary of material provisions of the debt securities and the indenture is subject to, and qualified in its entirety by reference to, all of the provisions of the indenture applicable to a particular series of debt securities. We urge you to read the applicable prospectus supplements and any related free writing prospectuses related to the debt securities that we may offer under this prospectus, as well as the complete indenture that contains the terms of the debt securities.

General

The indenture does not limit the amount of debt securities that we may issue. It provides that we may issue debt securities up to the principal amount that we may authorize and may be in any currency or currency unit that we may designate. Except for the limitations on consolidation, merger and sale of all or substantially all of our assets contained in the indenture, the terms of the indenture do not contain any covenants or other provisions designed to give holders of any debt securities protection against changes in our operations, financial condition or transactions involving us.

We may issue the debt securities issued under the indenture as “discount securities,” which means they may be sold at a discount below their stated principal amount. These debt securities, as well as other debt securities that are not issued at a discount, may be issued with “original issue discount,” or OID, for U.S. federal income tax purposes because of interest payment and other characteristics or terms of the debt securities. Material U.S. federal income tax considerations applicable to debt securities issued with OID will be described in more detail in any applicable prospectus supplement.

We will describe in the applicable prospectus supplement the terms of the series of debt securities being offered, including:

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Conversion or Exchange Rights

We will set forth in the applicable prospectus supplement the terms on which a series of debt securities may be convertible into or exchangeable for our common stock or our other securities. We will include provisions as to settlement upon conversion or exchange and whether conversion or exchange is mandatory, at the option of the holder or at our option. We may include provisions pursuant to which the number of shares of our common stock or our other securities that the holders of the series of debt securities receive would be subject to adjustment.

Consolidation, Merger or Sale

Unless we provide otherwise in the prospectus supplement applicable to a particular series of debt securities, the indenture will not contain any covenant that restricts our ability to merge or consolidate, or sell, convey, transfer or otherwise dispose of our assets as an entirety or substantially as an entirety. However, any successor to or acquiror of such assets (other than a subsidiary of ours) must assume all of our obligations under the indenture or the debt securities, as appropriate.

Events of Default under the Indenture

Unless we provide otherwise in the prospectus supplement applicable to a particular series of debt securities, the following are events of default under the indenture with respect to any series of debt securities that we may issue:

If an event of default with respect to debt securities of any series occurs and is continuing, other than an event of default specified in the last bullet point above, the trustee or the holders of at least 25% in aggregate principal

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amount of the outstanding debt securities of that series, by notice to us in writing, and to the trustee if notice is given by such holders, may declare the unpaid principal of, premium, if any, and accrued interest, if any, due and payable immediately. If an event of default specified in the last bullet point above occurs with respect to us, the principal amount of and accrued interest, if any, of each issue of debt securities then outstanding shall be due and payable without any notice or other action on the part of the trustee or any holder.

The holders of a majority in principal amount of the outstanding debt securities of an affected series may waive any default or event of default with respect to the series and its consequences, except defaults or events of default regarding payment of principal, premium, if any, or interest, unless we have cured the default or event of default in accordance with the indenture. Any waiver shall cure the default or event of default.

Subject to the terms of the indenture, if an event of default under an indenture shall occur and be continuing, the trustee will be under no obligation to exercise any of its rights or powers under such indenture at the request or direction of any of the holders of the applicable series of debt securities, unless such holders have offered the trustee reasonable indemnity. The holders of a majority in principal amount of the outstanding debt securities of any series will have the right to direct the time, method and place of conducting any proceeding for any remedy available to the trustee, or exercising any trust or power conferred on the trustee, with respect to the debt securities of that series, provided that:

A holder of the debt securities of any series will have the right to institute a proceeding under the indenture or to appoint a receiver or trustee, or to seek other remedies only if:

These limitations do not apply to a suit instituted by a holder of debt securities if we default in the payment of the principal, premium, if any, or interest on, the debt securities.

We will periodically file statements with the trustee regarding our compliance with specified covenants in the indenture.

Modification of Indenture; Waiver

We and the trustee may change an indenture without the consent of any holders with respect to specific matters:

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In addition, under the indenture, the rights of holders of a series of debt securities may be changed by us and the trustee with the written consent of the holders of at least a majority in aggregate principal amount of the outstanding debt securities of each series that is affected. However, unless we provide otherwise in the prospectus supplement applicable to a particular series of debt securities, we and the trustee may make the following changes only with the consent of each holder of any outstanding debt securities affected:

Discharge

Each indenture provides that we can elect to be discharged from our obligations with respect to one or more series of debt securities, except for specified obligations, including obligations to:

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In order to exercise our rights to be discharged, we must deposit with the trustee money or government obligations sufficient to pay all the principal of, any premium, if any, and interest on, the debt securities of the series on the dates payments are due.

Form, Exchange and Transfer

We will issue the debt securities of each series only in fully registered form without coupons and, unless we provide otherwise in the applicable prospectus supplement, in denominations of $1,000 and any integral multiple thereof. The indenture provides that we may issue debt securities of a series in temporary or permanent global form and as book-entry securities that will be deposited with, or on behalf of, The Depository Trust Company, or DTC, or another depositary named by us and identified in the applicable prospectus supplement with respect to that series. To the extent the debt securities of a series are issued in global form and as book-entry, a description of terms relating to such securities will be set forth in the applicable prospectus supplement.

At the option of the holder, subject to the terms of the indenture and the limitations applicable to global securities described in the applicable prospectus supplement, the holder of the debt securities of any series can exchange the debt securities for other debt securities of the same series, in any authorized denomination and of like tenor and aggregate principal amount.

Subject to the terms of the indenture and the limitations applicable to global securities set forth in the applicable prospectus supplement, holders of the debt securities may present the debt securities for exchange or for registration of transfer, duly endorsed or with the form of transfer endorsed thereon duly executed if so required by us or the security registrar, at the office of the security registrar or at the office of any transfer agent designated by us for this purpose. Unless otherwise provided in the debt securities that the holder presents for transfer or exchange, we will impose no service charge for any registration of transfer or exchange, but we may require payment of any taxes or other governmental charges.

We will name in the applicable prospectus supplement the security registrar, and any transfer agent in addition to the security registrar, that we initially designate for any debt securities. We may at any time designate additional transfer agents or rescind the designation of any transfer agent or approve a change in the office through which any transfer agent acts, except that we will be required to maintain a transfer agent in each place of payment for the debt securities of each series.

If we elect to redeem the debt securities of any series, we will not be required to:

Information Concerning the Trustee

The trustee, other than during the occurrence and continuance of an event of default under an indenture, undertakes to perform only those duties as are specifically set forth in the applicable indenture. Upon an event of default under an indenture, the trustee must use the same degree of care as a prudent person would exercise or use in the conduct of his or her own affairs. Subject to this provision, the trustee is under no obligation to exercise any of the powers given it by the indenture at the request of any holder of debt securities unless it is offered reasonable security and indemnity against the costs, expenses and liabilities that it might incur.

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Payment and Paying Agents

Unless we otherwise indicate in the applicable prospectus supplement, we will make payment of the interest on any debt securities on any interest payment date to the person in whose name the debt securities, or one or more predecessor securities, are registered at the close of business on the regular record date for the interest.

We will pay principal of and any premium and interest on the debt securities of a particular series at the office of the paying agents designated by us, except that unless we otherwise indicate in the applicable prospectus supplement, we will make interest payments by check that we will mail to the holder or by wire transfer to certain holders. Unless we otherwise indicate in the applicable prospectus supplement, we will designate the corporate trust office of the trustee as our sole paying agent for payments with respect to debt securities of each series. We will name in the applicable prospectus supplement any other paying agents that we initially designate for the debt securities of a particular series. We will maintain a paying agent in each place of payment for the debt securities of a particular series.

All money we pay to a paying agent or the trustee for the payment of the principal of or any premium or interest on any debt securities that remains unclaimed at the end of two years after such principal, premium or interest has become due and payable will be repaid to us, and the holder of the debt security thereafter may look only to us for payment thereof.

Governing Law

The indenture and the debt securities will be governed by and construed in accordance with the internal laws of the State of New York, except to the extent that the Trust Indenture Act of 1939 is applicable.

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DESCRIPTION OF WARRANTS

The following description, together with the additional information we may include in any applicable prospectus supplement and in any related free writing prospectus that we may authorize to be distributed to you, summarizes the material terms and provisions of the warrants that we may offer under this prospectus, which may consist of warrants to purchase common stock, preferred stock and/or debt securities and may be issued in one or more series. Warrants may be offered independently or in combination with common stock, preferred stock or debt securities offered by any prospectus supplement. While the terms we have summarized below will apply generally to any warrants that we may offer under this prospectus, we will describe the particular terms of any series of warrants in more detail in the applicable prospectus supplement. The following description of warrants will apply to the warrants offered by this prospectus unless we provide otherwise in the applicable prospectus supplement. The applicable prospectus supplement for a particular series of warrants may specify different or additional terms.

We have filed forms of the warrant agreements and forms of warrant certificates containing the terms of the warrants that may be offered as exhibits to the registration statement of which this prospectus is a part. We will file as exhibits to the registration statement of which this prospectus is a part, or will incorporate by reference from reports that we file with the SEC, the form of warrant and/or the warrant agreement and warrant certificate, as applicable, that contain the terms of the particular series of warrants we are offering, and any supplemental agreements, before the issuance of such warrants. The following summaries of material terms and provisions of the warrants are subject to, and qualified in their entirety by reference to, all the provisions of the form of warrant and/or the warrant agreement and warrant certificate, as applicable, and any supplemental agreements applicable to a particular series of warrants that we may offer under this prospectus. We urge you to read the applicable prospectus supplement related to the particular series of warrants that we may offer under this prospectus, as well as any related free writing prospectus, and the complete form of warrant and/or the warrant agreement and warrant certificate, as applicable, and any supplemental agreements, that contain the terms of the warrants.

General

We will describe in the applicable prospectus supplement the terms of the series of warrants being offered, including, to the extent applicable:

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Before exercising their warrants, holders of warrants will not have any of the rights of holders of the securities purchasable upon such exercise, including:

Exercise of Warrants

Each warrant will entitle the holder to purchase the securities that we specify in the applicable prospectus supplement at the exercise price that we describe in the applicable prospectus supplement. The warrants may be exercised as set forth in the prospectus supplement relating to the warrants offered. Unless we otherwise specify in the applicable prospectus supplement, warrants may be exercised at any time up to the specified time on the expiration date that we set forth in the applicable prospectus supplement. After the close of business on the expiration date, unexercised warrants will become void.

Upon receipt of payment and the warrant or warrant certificate, as applicable, properly completed and duly executed at the corporate trust office of the warrant agent, if any, or any other office, including ours, indicated in the prospectus supplement, we will, as soon as practicable, issue and deliver the securities purchasable upon such exercise. If less than all of the warrants (or the warrants represented by such warrant certificate) are exercised, a new warrant or a new warrant certificate, as applicable, will be issued for the remaining warrants.

Governing Law

Unless we provide otherwise in the applicable prospectus supplement, the warrants and warrant agreements, and any claim, controversy or dispute arising under or related to the warrants or warrant agreements, will be governed by and construed in accordance with the laws of the State of New York.

Enforceability of Rights by Holders of Warrants

Each warrant agent, if any, will act solely as our agent under the applicable warrant agreement and will not assume any obligation or relationship of agency or trust with any holder of any warrant. A single bank or trust company may act as warrant agent for more than one issue of warrants. A warrant agent will have no duty or responsibility in case of any default by us under the applicable warrant agreement or warrant, including any duty or responsibility to initiate any proceedings at law or otherwise, or to make any demand upon us. Any holder of a warrant may, without the consent of the related warrant agent or the holder of any other warrant, enforce by appropriate legal action its right to exercise, and receive the securities purchasable upon exercise of, its warrants.

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LEGAL OWNERSHIP OF SECURITIES

We can issue securities in registered form or in the form of one or more global securities. We describe global securities in greater detail below. We refer to those persons who have securities registered in their own names on the books that we or any applicable trustee, depositary or warrant agent maintain for this purpose as the “holders” of those securities. These persons are the legal holders of the securities. We refer to those persons who, indirectly through others, own beneficial interests in securities that are not registered in their own names, as “indirect holders” of those securities. As we discuss below, indirect holders are not legal holders, and investors in securities issued in book-entry form or in street name will be indirect holders.

Book-Entry Holders

We may issue securities in book-entry form only, as we will specify in the applicable prospectus supplement. This means securities may be represented by one or more global securities registered in the name of a financial institution that holds them as depositary on behalf of other financial institutions that participate in the depositary’s book-entry system. These participating institutions, which are referred to as participants, in turn, hold beneficial interests in the securities on behalf of themselves or their customers.

Only the person in whose name a security is registered is recognized as the holder of that security. Securities issued in global form will be registered in the name of the depositary or its participants. Consequently, for securities issued in global form, we will recognize only the depositary as the holder of the securities, and we will make all payments on the securities to the depositary. The depositary passes along the payments it receives to its participants, which in turn pass the payments along to their customers who are the beneficial owners. The depositary and its participants do so under agreements they have made with one another or with their customers; they are not obligated to do so under the terms of the securities.

As a result, investors in a global security will not own securities directly. Instead, they will own beneficial interests in a global security, through a bank, broker or other financial institution that participates in the depositary’s book-entry system or holds an interest through a participant. As long as the securities are issued in global form, investors will be indirect holders, and not legal holders, of the securities.

Street Name Holders

We may terminate a global security or issue securities in non-global form. In these cases, investors may choose to hold their securities in their own names or in “street name.” Securities held by an investor in street name would be registered in the name of a bank, broker or other financial institution that the investor chooses, and the investor would hold only a beneficial interest in those securities through an account he or she maintains at that institution.

For securities held in street name, we or any applicable trustee or depositary will recognize only the intermediary banks, brokers and other financial institutions in whose names the securities are registered as the holders of those securities, and we or any applicable trustee or depositary will make all payments on those securities to them. These institutions pass along the payments they receive to their customers who are the beneficial owners, but only because they agree to do so in their customer agreements or because they are legally required to do so. Investors who hold securities in street name will be indirect holders, not holders, of those securities.

Legal Holders

Our obligations, as well as the obligations of any applicable trustee and of any third parties employed by us or a trustee, run only to the legal holders of the securities. We do not have obligations to investors who hold beneficial interests in global securities, in street name or by any other indirect means. This will be the case whether an investor chooses to be an indirect holder of a security or has no choice because we are issuing the securities only in global form.

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For example, once we make a payment or give a notice to the legal holder, we have no further responsibility for the payment or notice even if that legal holder is required, under agreements with its participants or customers or by law, to pass it along to the indirect holders but does not do so. Similarly, we may want to obtain the approval of the legal holders to amend an indenture, to relieve us of the consequences of a default or of our obligation to comply with a particular provision of the indenture or for other purposes. In such an event, we would seek approval only from the holders, and not the indirect holders, of the securities. Whether and how the legal holders contact the indirect holders is up to the legal holders.

Special Considerations for Indirect Holders

If you hold securities through a bank, broker or other financial institution, either in book-entry form or in street name, you should check with your own institution to find out:

Global Securities

A global security is a security that represents one or any other number of individual securities held by a depositary. Generally, all securities represented by the same global securities will have the same terms.

Each security issued in book-entry form will be represented by a global security that we issue to, deposit with and register in the name of a financial institution or its nominee that we select. The financial institution that we select for this purpose is called the depositary. Unless we specify otherwise in the applicable prospectus supplement, DTC will be the depositary for all securities issued in book-entry form.

A global security may not be transferred to or registered in the name of anyone other than the depositary, its nominee or a successor depositary, unless special termination situations arise. We describe those situations below under “Special Situations When a Global Security Will Be Terminated.” As a result of these arrangements, the depositary, or its nominee, will be the sole registered owner and legal holder of all securities represented by a global security, and investors will be permitted to own only beneficial interests in a global security. Beneficial interests must be held by means of an account with a broker, bank or other financial institution that in turn has an account with the depositary or with another institution that does. Thus, an investor whose security is represented by a global security will not be a legal holder of the security, but only an indirect holder of a beneficial interest in the global security.

If the prospectus supplement for a particular security indicates that the security will be issued in global form only, then the security will be represented by a global security at all times unless and until the global security is terminated. If termination occurs, we may issue the securities through another book-entry clearing system or decide that the securities may no longer be held through any book-entry clearing system.

Special Considerations for Global Securities

The rights of an indirect holder relating to a global security will be governed by the account rules of the investor’s financial institution and of the depositary, as well as general laws relating to securities transfers. We

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do not recognize an indirect holder as a holder of securities and instead deal only with the depositary that holds the global security.

If securities are issued only in the form of a global security, an investor should be aware of the following:

There may be more than one financial intermediary in the chain of ownership for an investor. We do not monitor and are not responsible for the actions of any of those intermediaries.

Special Situations When a Global Security Will Be Terminated

In a few special situations described below, the global security will terminate and interests in it will be exchanged for physical certificates representing those interests. After that exchange, the choice of whether to hold securities directly or in street name will be up to the investor. Investors must consult their own banks, brokers or other financial institutions to find out how to have their interests in securities transferred to their own name, so that they will be direct holders. We have described the rights of holders and street name investors above.

Unless we provide otherwise in the applicable prospectus supplement, the global security will terminate when the following special situations occur:

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The prospectus supplement may also list additional situations for terminating a global security that would apply only to the particular series of securities covered by the applicable prospectus supplement. When a global security terminates, the depositary, and not we or any applicable trustee, is responsible for deciding the names of the institutions that will be the initial direct holders.

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SELLING STOCKHOLDERS

This prospectus also relates to the possible resale by certain of our stockholders, who we refer to in this prospectus as the selling stockholders, of up to 1,000,000 shares of our common stock that were issued and outstanding prior to the date of the registration statement of which this prospectus forms a part. These shares of common stock were originally acquired by the selling stockholders (i) through private placements of shares of our preferred stock that were converted into shares of common stock in connection with our initial public offering, (ii) as consideration for the acquisition of other business, (iii) as compensatory stock awards or (iv) upon the exercise of options to purchase common stock.

The applicable prospectus supplement will set forth the name of each of the selling stockholders and the number of securities beneficially owned by such selling stockholder that are covered by such applicable prospectus supplement. The applicable prospectus supplement will also disclose whether any of the selling stockholders has held any position or office with, has been employed by, or otherwise has had a material relationship with us during the three years prior to the date of the applicable prospectus supplement.

The selling stockholders shall not sell any shares of our common stock pursuant to this prospectus until we have identified such selling stockholders and the shares being offered for resale by such selling stockholders in a subsequent prospectus supplement. However, the selling stockholders may sell or transfer all or a portion of their shares of our common stock pursuant to any available exemption from the registration requirements of the Securities Act.

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PLAN OF DISTRIBUTION

We or the selling stockholders may sell our securities from time to time:

We or the selling stockholders may directly solicit offers to purchase securities, or agents may be designated to solicit such offers. In any applicable prospectus supplement relating to such offering, we will name any agent that could be viewed as an underwriter under the Securities Act and describe any commissions that we or the selling stockholders must pay to any such agent. Any such agent will be acting on a best efforts basis for the period of its appointment or, if indicated in the applicable prospectus supplement, on a firm commitment basis. This prospectus may be used in connection with any offering of our securities through any of these methods or other methods described in the applicable prospectus supplement.

The distribution of our securities stock may be effected from time to time in one or more transactions:

Each prospectus supplement will describe the method of distribution of the securities and any applicable restrictions.

A prospectus supplement or supplements (and any related free writing prospectus that we may authorize to be provided to you with respect to a particular offering) will describe the terms of the offering of our securities, including the following:

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If any underwriters or agents are used in the sale of our securities in respect of which this prospectus is delivered, we or the selling stockholders will enter into an underwriting agreement, sales agreement or other agreement with them at the time of sale to them, and we will set forth in the applicable prospectus supplement relating to such offering the names of the underwriters or agents and the terms of the related agreement with them.

In connection with the offering of securities, we or the selling stockholders may grant to the underwriters an option to purchase additional securities with an additional underwriting commission, as may be set forth in the applicable prospectus supplement. If the selling stockholders grant any such option, the terms of such option will be set forth in the applicable prospectus supplement for such securities.

If a dealer is used in the sale of the securities in respect of which the prospectus is delivered, we or the selling stockholders will sell such securities to the dealer, as principal. The dealer, who may be deemed to be an “underwriter” as that term is defined in the Securities Act, may then resell such securities to the public at varying prices to be determined by such dealer at the time of resale.

We or the selling stockholders may provide agents and underwriters with indemnification against civil liabilities, including liabilities under the Securities Act, or contribution with respect to payments that the agents or underwriters may make with respect to those liabilities. In addition, we will indemnify the selling stockholders against certain civil liabilities, including certain liabilities under the Securities Act, and the selling stockholders will be entitled to contribution from us with respect to those liabilities. The selling stockholders will indemnify us against certain civil liabilities, including liabilities under the Securities Act, and we will be entitled to contribution from the selling stockholders with respect to those liabilities.

If so indicated in the applicable prospectus supplement, we or the selling stockholders will authorize underwriters or other persons acting as agents to solicit offers by certain institutions to purchase securities from us or the selling stockholders pursuant to delayed delivery contracts providing for payment and delivery on the date stated in the applicable prospectus supplement. Each contract will be for an amount not less than, and the aggregate amount of securities sold pursuant to such contracts shall not be less nor more than, the respective amounts stated in the applicable prospectus supplement. Institutions with whom the contracts, when authorized, may be made include commercial and savings banks, insurance companies, pension funds, investment companies, educational and charitable institutions and other institutions. Delayed delivery contracts will not be subject to any conditions except that:

Offered securities may also be offered and sold, if so indicated in the applicable prospectus supplement, in connection with a remarketing upon their purchase, in accordance with a redemption or repayment pursuant to their terms, or otherwise, by one or more remarketing firms, acting as principals for their own accounts or as agents for us or the selling stockholders. Any remarketing firm will be identified and the terms of its agreement, if any, with us or the selling stockholders and its compensation will be described in the applicable prospectus supplement. Remarketing firms may be deemed to be underwriters in connection with their remarketing of offered securities.

Certain agents, underwriters and dealers, and their associates and affiliates, may be customers of, have borrowing relationships with, engage in other transactions with, or perform services, including investment banking services,

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for us or one or more of our respective affiliates and/or the selling stockholders or one or more of its respective affiliates in the ordinary course of business for which they receive compensation.

In order to facilitate the offering of our securities, any underwriters may engage in transactions that stabilize, maintain or otherwise affect the price of the securities or any other securities the prices of which may be used to determine payments on such securities. Specifically, any underwriters may overallot in connection with the offering, creating a short position for their own accounts. In addition, to cover overallotments or to stabilize the price of the securities or of any such other securities, the underwriters may bid for, and purchase, the securities or any such other securities in the open market. Finally, in any offering of our securities through a syndicate of underwriters, the underwriting syndicate may reclaim selling concessions allowed to an underwriter or a dealer for distributing the securities in the offering if the syndicate repurchases previously distributed securities in transactions to cover syndicate short positions, in stabilization transactions or otherwise. Any of these activities may stabilize or maintain the market price of the securities above independent market levels. Any such underwriters are not required to engage in these activities and may end any of these activities at any time.

We or the selling stockholders may engage in at the market offerings into an existing trading market in accordance with Rule 415(a)(4) under the Securities Act. In addition, we or the selling stockholders may enter into derivative transactions with third parties, or sell securities not covered by this prospectus to third parties in privately negotiated transactions. If the applicable prospectus supplement so indicates, in connection with those derivatives, the third parties may sell securities covered by this prospectus and the applicable prospectus supplement, including in short sale transactions. If so, the third party may use securities pledged by us or the selling stockholders or borrowed from us or the selling stockholders or others to settle those sales or to close out any related open borrowings of stock, and may use securities received in settlement of those derivatives to close out any related open borrowings of stock. The third party in such sale transactions will be an underwriter and, if not identified in this prospectus, will be named in the applicable prospectus supplement (or a post-effective amendment). In addition, we or the selling stockholders may otherwise loan or pledge securities to a financial institution or other third party that in turn may sell the securities short using this prospectus and an applicable prospectus supplement. Such financial institution or other third party may transfer its economic short position to investors in our securities or in connection with a concurrent offering of other securities.

Under Rule 15c6-1 of the Exchange Act, trades in the secondary market generally are required to settle in two business days, unless the parties to any such trade expressly agree otherwise. The applicable prospectus supplement may provide that the original issue date for your securities may be more than two scheduled business days after the trade date for your securities. Accordingly, in such a case, if you wish to trade securities on any date prior to the second business day before the original issue date for your securities, you will be required, by virtue of the fact that your securities initially are expected to settle in more than two scheduled business days after the trade date for your securities, to make alternative settlement arrangements to prevent a failed settlement.

In compliance with the guidelines of the Financial Industry Regulatory Authority, Inc., or FINRA, the aggregate maximum discount, commission or agency fees or other items constituting underwriting compensation to be received by any FINRA member or independent broker-dealer will not exceed 8% of the proceeds from any offering pursuant to this prospectus and any applicable prospectus supplement.

The specific terms of any lock-up provisions in respect of any given offering will be described in the applicable prospectus supplement.

The anticipated date of delivery of offered securities will be set forth in the applicable prospectus supplement relating to each offer.

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LEGAL MATTERS

Cooley LLP, Boston, Massachusetts will pass upon the validity of the securities offered hereby unless otherwise indicated in the applicable prospectus supplement. Any underwriters will also be advised about the validity of the securities and other legal matters by their own counsel, which will be named in the applicable prospectus supplement.

EXPERTS

The consolidated financial statements of Everbridge, Inc. as of December 31, 2016 and 2015, and for each of the years in the three-year period ended December 31, 2016, have been incorporated by reference herein and in the registration statement in reliance upon the report of KPMG LLP, independent registered public accounting firm, incorporated by reference herein, and upon the authority of said firm as experts in accounting and auditing.

The financial statements of IDV Solutions, LLC as of December 31, 2016, and for the year ended December 31, 2016, have been incorporated by reference herein and in the registration statement in reliance upon the report of Plante & Moran, PLLC, an independent accounting firm, incorporated by reference herein, and upon the authority of said firm as experts in accounting and auditing.

WHERE YOU CAN FIND MORE INFORMATION

We are subject to the information requirements of the Exchange Act and, in accordance therewith, file annual, quarterly and special reports, proxy statements and other information with the SEC. You may read and copy any document we file at the SEC’s Public Reference Room at 100 F Street, N.E., Washington, D.C. 20549. You may call the SEC at 1-800-SEC-0330 for further information on the operation of the Public Reference Room. These documents also may be accessed through the SEC’s electronic data gathering, analysis and retrieval system, or EDGAR, via electronic means, including the SEC’s home page on the Internet (www.sec.gov).

This prospectus is part of the registration statement on Form S-3 we filed with the SEC under the Securities Act and does not contain all the information set forth in the registration statement. Whenever a reference is made in this prospectus to any of our contracts, agreements or other documents, the reference may not be complete and you should refer to the exhibits that are a part of the registration statement or the exhibits to the reports or other documents incorporated by reference into this prospectus for a copy of such contract, agreement or other document.

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INCORPORATION OF CERTAIN INFORMATION BY REFERENCE

The SEC allows us to “incorporate by reference” the information and reports we file with it, which means that we can disclose important information to you by referring you to these documents. The information incorporated by reference is an important part of this prospectus, and information that we file later with the SEC will automatically update and supersede the information already incorporated by reference. We are incorporating by reference the documents listed below, which we have already filed with the SEC, and any future filings we make with the SEC under Sections 13(a), 13(c), 14 or 15(d) of the Exchange Act (other than Current Reports or portions furnished under Items 2.02 or 7.01 of Form 8-K), including all filings made after the date of the filing of this registration statement of which this prospectus is a part and prior to the effectiveness of this registration statement until we file a post-effective amendment that indicates the termination of the offering of the securities covered by this prospectus:

Upon request, we will provide, without charge, to each person, including any beneficial owner, to whom a copy of this prospectus is delivered, a copy of the documents incorporated by reference into this prospectus but not delivered with the prospectus. You may request a copy of these filings, and any exhibits we have specifically incorporated by reference as an exhibit in this prospectus, at no cost by writing or telephoning us at the following address: Everbridge, Inc., 25 Corporate Drive, Suite 400, Burlington, Massachusetts 01803, Attention: General Counsel, or by telephone request to (818) 230-9700.

Neither we nor any selling stockholder have authorized anyone to provide you with information other than what is incorporated by reference or provided in this prospectus or any applicable prospectus supplement. Neither we nor any selling stockholder are making an offer of these securities in any state where the offer is not permitted. You should not assume that the information in this prospectus or in the documents incorporated by reference is accurate as of any date other than the date on the front of this prospectus or those documents.

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$100,000,000

    % Convertible Senior Notes due 2022

Prospectus

                    , 2017