[Form 4] DexCom, Inc. Insider Trading Activity

Rhea-AI Filing Summary

DexCom, Inc. (DXCM) – Form 4 insider transaction

EVP & Chief HR Officer Sadie Stern reported the sale of 1,466 common shares on 26-Jun-2025 at an average price of $85.06, generating gross proceeds of roughly $125,000. The transaction was executed under a pre-arranged Rule 10b5-1 trading plan adopted 20-Feb-2025, signalling that timing was automated rather than discretionary.

Following the sale, Stern’s beneficial ownership stands at 108,155 shares, of which 74,450 are unvested RSUs scheduled to vest between 2026 and 2028. The reported sale represents ~1.4% of her post-transaction holdings, leaving her overall exposure to DexCom equity largely intact.

No derivative transactions, option exercises, or additional sales were disclosed, and there is no indication of strategic changes or financial performance data within this filing.

Insights

Financial Analyst

TL;DR: Minor 1,466-share sale under 10b5-1 plan; immaterial to DXCM valuation.

The filing shows a routine disposal representing about 1.4% of Ms. Stern’s DXCM stake and a negligible <0.01% of the company’s 400 m outstanding shares. Because the sale was executed via a 10b5-1 plan, the timing is pre-scheduled, reducing signalling risk. Retention of more than 108 k shares, including sizable unvested RSUs, suggests continued alignment with shareholders. The transaction has no bearing on revenues, margins, or guidance and is therefore not materially impactful for valuation or trading sentiment.

Corporate Governance Expert

TL;DR: Governance-compliant, pre-planned sale; neutral insider-sentiment read.

The presence of a 10b5-1 plan adopted months in advance demonstrates good governance practice and mitigates concerns about opportunistic selling ahead of material events. The residual equity exposure remains high, preserving incentives. Given the limited size of the sale and ongoing vesting schedule, investors should view the filing as routine housekeeping rather than a negative sentiment indicator.

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).

X

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^*

Stern Sadie

(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 HR Officer

3. Date of Earliest Transaction (Month/Day/Year)
06/26/2025

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	06/26/2025		S		1,466(1)	D	$85.06	108,155(2)	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. On February 20, 2025, Ms. Stern adopted a 10b5-1 Plan. This 10b5-1 Plan allows the orderly disposition of shares owned by Ms. Stern. The shares set forth above were sold pursuant to the 10b5-1 Plan.

2. Included in this number are 74,450 unvested restricted stock units, 29,922 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, 14,474 of which were granted on March 8, 2024 and shall vest through March 8, 2027, and 7,256 of which were granted on March 8, 2023 and shall vest through March 8, 2026.

Remarks:

Exhibit 24 - Power of Attorney

	/s/ Jereme M. Sylvain, as Attorney-in-Fact for Sadie Stern	06/30/2025
	** 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

How many DexCom (DXCM) shares did EVP Sadie Stern sell?

She sold 1,466 common shares on 26-Jun-2025.

What was the sale price of the DXCM shares?

The shares were sold at an average price of $85.06 per share.

Was the transaction executed under a Rule 10b5-1 plan?

Yes. The sale was made pursuant to a 10b5-1 trading plan adopted on 20-Feb-2025.

How many DXCM shares does Sadie Stern still own after the sale?

She now beneficially owns 108,155 shares, including 74,450 unvested RSUs.

Is this insider sale considered material to DexCom investors?

Given its small size (≈1.4% of her holdings and <0.01% of shares outstanding), the sale is viewed as not materially impactful.