DEXCOM INC — Director's Dealing 2018

May 11, 2018

SEC Form 4 — Statement of Changes in Beneficial Ownership

Issuer: DEXCOM INC (DXCM)
CIK: 0001093557
Period of Report: 2018-05-08

Reporting Person: Leach Jacob Steven (SVP, Research & Development)

Non-Derivative Transactions

Date	Security	Code	Shares	Price	A/D	Holdings After	Ownership
2018-05-08	Common Stock	M	1923	$3.19	Acquired	100801	Direct
2018-05-08	Common Stock	S	1923	$84.9536	Disposed	98878	Direct
2018-05-09	Common Stock	M	8542	$9.78	Acquired	107420	Direct
2018-05-09	Common Stock	S	8542	$84.7716	Disposed	98878	Direct
2018-05-09	Common Stock	M	203	$7.27	Acquired	99081	Direct
2018-05-09	Common Stock	S	203	$84.7716	Disposed	98878	Direct
2018-05-08	Common Stock	S	2500	$85.1495	Disposed	47600	Indirect

Derivative Transactions

Date	Security	Exercise Price	Code	Shares	A/D	Expiration	Underlying	Ownership
2018-05-08	Non-Qualified Stock Option (right to buy)	$3.19	M	1923	Disposed	2018-12-11	Common Stock (1923)	Direct
2018-05-09	Non-Qualified Stock Option (right to buy)	$7.27	M	203	Disposed	2019-11-20	Common Stock (203)	Direct
2018-05-09	Non-Qualified Stock Option (right to buy)	$9.78	M	8542	Disposed	2020-02-18	Common Stock (8542)	Direct

Holdings (Non-Derivative)

Security	Shares	Ownership
Common Stock	12000	Indirect

Footnotes

F1: Included in this number are 56,182 unvested restricted stock units, 30,093 of which were granted on March 8, 2018 and shall vest through March 8, 2021, 15,422 of which were granted on March 8, 2017 and shall vest through March 8, 2020 and 10,667 of which were granted on March 8, 2016 shall vest through March 8, 2019.

F2: This transaction was executed in multiple trades at prices ranging from $84.77 to $84.81. 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 issuer full information regarding the number of shares and prices at which the transactions were effected.

F3: This transaction was executed in multiple trades at prices ranging from $85.14 to $85.18. 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 issuer full information regarding the number of shares and prices at which the transactions were effected.

F4: Shares are held by the Kyndra S. Leach Trust UAD 12/12/2012, with respect to which the reporting person's spouse is a trustee.

F5: Shares are held by the Gregg Family Grandchildren's Trust UAD 12/30/2010, with respect to which the reporting person's spouse is a trustee.