[Form 4] DEXCOM INC Insider Trading Activity

Rhea-AI Filing Summary

DXCM executive vice president and chief financial officer Jereme M. Sylvain reported equity award activity in company common stock. On January 29, 2026, he acquired 7,123 shares at $0 upon vesting of performance-based restricted stock units granted on March 8, 2023 after performance goals were achieved.

On the same date, 2,652 shares were withheld at $73.36 per share to satisfy tax obligations related to this vesting, which the footnotes clarify was not a sale. After these transactions, he directly beneficially owned 123,207 shares, including 83,328 unvested restricted stock units scheduled to vest between March 8, 2026 and March 8, 2028 and 79 shares acquired under the company’s employee stock purchase plan.

Insider Trade Summary

2 transactions reported

Mixed 2 txns

Insider Sylvain Jereme M

Role EVP, Chief Financal Officer

Type	Security	Shares	Price	Value
Grant/Award	Common Stock	7,123	$0.00	--
Tax Withholding	Common Stock	2,652	$73.36	$195K

Holdings After Transaction: Common Stock — 125,859 shares (Direct)

Footnotes (1)

1. Represents shares issued to the Reporting Person upon vesting of performance-based restricted stock units (PSUs) granted to the Reporting Person on March 8, 2023, resulting from achievement of performance conditions under the PSUs. Represents the number of shares required to be withheld by the Issuer to cover tax withholding and remittance obligations in connection with the net settlement of PSUs and does not represent a sale by the Reporting Person. Included in this number are 83,328 unvested restricted stock units, 35,906 of which were granted on March 8, 2025 and shall vest through March 8, 2028, 22,798 of which were granted on March 8, 2025 and shall vest through March 8, 2027, 17,368 of which were granted on March 8, 2024 and shall vest through March 8, 2027, 7,256 of which were granted on March 8, 2023 and shall vest through March 8, 2026, and 79 additional shares acquired under the Issuer's Amended and Restated 2015 Employee Stock Purchase Plan.

Form 4 Insider Transactions: What Each Field Means →

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0287
Estimated average burden
hours per response:			0.5

Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

Sylvain Jereme M

(Last) (First) (Middle)

6340 SEQUENCE DRIVE

(Street)

SAN DIEGO CA 92121

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
DEXCOM INC [ DXCM ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	EVP, Chief Financal Officer

3. Date of Earliest Transaction (Month/Day/Year)
01/29/2026

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	01/29/2026		A		7,123(1)	A	$0	125,859	D
Common Stock	01/29/2026		F		2,652(2)	D	$73.36	123,207(3)	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. Represents shares issued to the Reporting Person upon vesting of performance-based restricted stock units (PSUs) granted to the Reporting Person on March 8, 2023, resulting from achievement of performance conditions under the PSUs.

2. Represents the number of shares required to be withheld by the Issuer to cover tax withholding and remittance obligations in connection with the net settlement of PSUs and does not represent a sale by the Reporting Person.

3. Included in this number are 83,328 unvested restricted stock units, 35,906 of which were granted on March 8, 2025 and shall vest through March 8, 2028, 22,798 of which were granted on March 8, 2025 and shall vest through March 8, 2027, 17,368 of which were granted on March 8, 2024 and shall vest through March 8, 2027, 7,256 of which were granted on March 8, 2023 and shall vest through March 8, 2026, and 79 additional shares acquired under the Issuer's Amended and Restated 2015 Employee Stock Purchase Plan.

Remarks:

Exhibit 24 - Power of Attorney

	/s/ Jereme M. Sylvain	02/02/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What did DXCM executive Jereme M. Sylvain report in this Form 4 filing?

Jereme M. Sylvain reported equity award activity involving company common stock. He received shares from vested performance-based restricted stock units and had additional shares withheld to cover tax obligations tied to that vesting, while retaining a substantial direct ownership position afterward.

How many DXCM shares did the CFO receive from PSU vesting on January 29, 2026?

He received 7,123 DXCM common shares from the vesting of performance-based restricted stock units. These units were originally granted on March 8, 2023 and vested after performance conditions were achieved, increasing his directly held share count before tax withholding.

Were any DXCM shares sold by the CFO in this Form 4 transaction?

The filing specifies that 2,652 shares were withheld to cover tax withholding and remittance obligations. The footnote clearly states this withholding does not represent a sale by the reporting person, but rather a net share settlement for tax purposes.

What price was used for the DXCM share tax withholding in the Form 4?

The 2,652 DXCM shares withheld for taxes were valued at $73.36 per share. This per-share price reflects the value used to satisfy the reporting person’s tax obligations related to the vesting and net settlement of the performance-based restricted stock units.

How many DXCM shares does the CFO own after these transactions?

After the reported transactions, Jereme M. Sylvain beneficially owned 123,207 DXCM common shares directly. This total includes vested shares, 83,328 unvested restricted stock units scheduled to vest through various dates, and 79 additional shares from the employee stock purchase plan.

What unvested DXCM restricted stock units are included in the CFO’s holdings?

The filing notes 83,328 unvested restricted stock units within the total beneficial ownership. These include grants from March 8, 2023, 2024, and 2025, with portions scheduled to vest through March 8, 2026, March 8, 2027, and March 8, 2028 under the company’s equity plans.