[Form 4] DexCom, Inc. Insider Trading Activity

Rhea-AI Filing Summary

DexCom insider sale under pre-established plan; small number of shares sold. Michael Jon Brown, EVP and Chief Legal Officer of DexCom (DXCM), sold 500 shares of common stock on 08/15/2025 at a reported price of $80.29 per share. The sale was executed pursuant to a 10b5-1 trading plan adopted on 02/21/2025, which the filing states allows for orderly dispositions of his shares.

After the reported sale Mr. Brown beneficially owned 94,102 shares. The filing discloses that 86,490 of those shares are unvested restricted stock units, detailed by grant dates and vesting schedules (grants from 2022–2025 with vesting through March 8, 2028). The form is signed by an attorney-in-fact on 08/18/2025.

Positive

• Sale executed under a 10b5-1 plan, indicating the transaction followed a pre-established, documented program
• Detailed disclosure of unvested RSUs including grant dates and vesting schedules improves transparency

Negative

• Insider disposed of shares (500 shares sold), which could be viewed unfavorably by some investors despite being under a 10b5-1 plan

Insights

Securities Analyst

TL;DR: Officer sold a small number of shares under a pre-set 10b5-1 plan; holdings remain largely in unvested RSUs.

The filing documents a routine disposition of 500 shares at $80.29 on 08/15/2025 executed under a 10b5-1 plan adopted 02/21/2025. Such plans are commonly used to avoid timing concerns around insider trading windows. The remaining beneficial ownership of 94,102 shares is heavily weighted toward unvested restricted stock units (86,490 RSUs), which indicates future equity dilution potential as those units vest but does not represent immediate sellable stock. The transaction size is immaterial relative to total holdings disclosed here.

Corporate Governance Expert

TL;DR: Filing shows compliance with Rule 10b5-1 disclosure and standard reporting procedures.

The Form 4 records an insider sale pursuant to an explicit 10b5-1 plan, with the filing signed by an attorney-in-fact on 08/18/2025. The disclosure of the plan adoption date and granular RSU vesting schedules improves transparency about the nature of remaining holdings. There are no indications in this filing of unusual trading activity or departures from standard insider reporting obligations.

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
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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^*

Brown Michael Jon

(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 Legal Officer

3. Date of Earliest Transaction (Month/Day/Year)
08/15/2025

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	08/15/2025		S		500(1)	D	$80.29	94,102(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 21, 2025, Mr. Brown adopted a 10b5-1 Plan. This 10b5-1 Plan allows the orderly disposition of shares owned by Mr. Brown. The shares set forth above were sold pursuant to the 10b5-1 Plan.

2. Included in this number are 86,490 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, 7,256 of which were granted on March 8, 2023 and shall vest through March 8, 2026, and 12,040 of which were granted on March 8, 2022 and shall vest through March 8, 2026.

Remarks:

	/s/ Jereme M. Sylvain, as Attorney-in-Fact for Michael Jon Brown	08/18/2025
	** 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

What did Michael Jon Brown report on Form 4 for DXCM?

The filing reports a sale of 500 shares of DexCom common stock on 08/15/2025 at $80.29 per share, executed under a 10b5-1 plan.

Was the sale part of a pre-established trading plan for DXCM insider?

Yes. The sale was made pursuant to a 10b5-1 plan that Mr. Brown adopted on 02/21/2025.

How many DexCom shares did Mr. Brown beneficially own after the transaction?

He beneficially owned 94,102 shares following the reported transaction.

How many of Mr. Brown's shares are unvested restricted stock units?

The filing states 86,490 unvested RSUs, with specific grants and vesting through March 8, 2028 and earlier dates.

When was the Form 4 signed and filed?

The signature by an attorney-in-fact is dated 08/18/2025 in the filing.