DEXCOM INC — Director's Dealing 2013

Feb 28, 2013

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: DEXCOM INC (DXCM)
CIK: 0001093557
Period of Report: 2013-02-26

Reporting Person: Pacelli Steven Robert (EVP, Strategy & Corp. Dev.)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2013-02-26	Common Stock	M	30000	$3.19	Acquired	196052	Direct
2013-02-26	Common Stock	S	30000	$14.945	Disposed	166052	Direct
2013-02-27	Common Stock	M	20000	$3.19	Acquired	186052	Direct
2013-02-27	Common Stock	S	20000	$15.005	Disposed	166052	Direct
2013-02-28	Common Stock	M	25000	$3.19	Acquired	191052	Direct
2013-02-28	Common Stock	S	25000	$14.994	Disposed	166052	Direct

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2013-02-26	Non-Qualified Stock Option (right to buy)	$3.19	M	30000	Disposed	2018-12-11	Common Stock (30000)	Direct
2013-02-27	Non-Qualified Stock Option (right to buy)	$3.19	M	20000	Disposed	2018-12-11	Common Stock (20000)	Direct
2013-02-28	Non-Qualified Stock Option (right to buy)	$3.19	M	25000	Disposed	2018-12-11	Common Stock (25000)	Direct

Footnotes

F1: This transaction was executed in multiple trades at prices ranging from $14.89 to $15.00. The price above reflects the weighted average sale price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issurer full information regarding the number of shares and prices at which the transactions were effected.

F2: Included in this number are 118,028 unvested restricted stock units, 10,417 of which were granted on March 8, 2011 and shall vest through June 8, 2013, 35,990 of which were granted on March 8, 2011 and shall vest through March 8, 2014, and 71,621 of which were granted on March 8, 2012 and shall vest through March 8, 2015.

F3: This transaction was executed in multiple trades at prices ranging from $15.00 to $15.02. The price above reflects the weighted average sale price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issurer full information regarding the number of shares and prices at which the transactions were effected.

F4: This transaction was executed in multiple trades at prices ranging from $14.89 to $15.10. The price above reflects the weighted average sale price. The reporting person hereby undertakes to provide upon request to the SEC staff, the issuer or a security holder of the issurer full information regarding the number of shares and prices at which the transactions were effected.