Transactions

DexCom Follow-On Offering

DexCom Announces Pricing of Follow-On Offering of 4,782,500 Shares of Common Stock

SAN DIEGO, CA (Business Wire) - April 27, 2006 - DexCom, Inc. (Nasdaq: DXCM) today announced the offering of 4,782,500 shares. 1,400,000 shares were sold by DexCom for total net proceeds of approximately $30.8 million, after deducting underwriting discounts and commissions and estimated offering expenses, and 3,382,500 shares were sold by selling stockholders. Piper Jaffray & Co. is the sole book-running manager for the offering. First Albany Capital Inc. is the co-lead manager and Lazard Capital Markets and Montgomery & Co., LLC are co-managers. DexCom has granted the underwriters a 30-day option to purchase up to an additional 717,375 shares to cover over allotments, if any. DexCom will not receive any proceeds from the sales of sares by the selling stockholders.

A registration statement relating to these securities has been filed with and declared effective by the Securities and Exchange Commission. This pres release shall not constitute an offer to sell or the solicitation of an offer to buy nor shall there be any sale of these securities in any state in which such offer, solicitation or sale would be unlawful prior to registration or qualification under the securities laws of any such state. Any offer will be made only by means of a prospectus included in the registration statement. A final prospectus relating to the offering may be obtained from the officers of Piper Jaffray & Co.

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About DexCom, Inc.

DexCom, Inc., headquartered in San Diego, California, is developing continuous glucose monitoring systems for people with diabetes.

Case Study

Summary

- DexCom develops, manufactures and markets continuous glucose monitoring systems for people with diabetes

- Following FDA approval of their short-term continuous glucose monitoring system, DexCom and certain shareholders chose to capitalize on its strong market position through a follow-on offering

- DexCom engaged Montgomery as a co-manager to help manage the process and strategically position the Company to potential investors

- The result of this process was a successful $132 million follow-on offering

Montgomery contributed significant value through:

- Hands-on execution from senior bankers throughout each step of the process

- Creation of a successful outcome. DexCom’s stock price increased 15% from file to offer and has increased over 5% since the offering