[Form 4] DexCom, Inc. Insider Trading Activity

Rhea-AI Filing Summary

Mark G. Foletta, a trustee and director of DexCom, Inc. (DXCM), reported sales of company stock executed on 08/15/2025 under a pre-existing 10b5-1 plan. The filing shows two sale transactions: 2,555 shares sold at a weighted average price of $81.0186 (individual trade prices ranged $80.29–$81.22) and 195 shares sold at $81.54. After these transactions, the filing reports beneficial holdings by The Foletta Family Trust of 51,316 and 51,121 shares respectively. The report also discloses 5,731 unvested restricted stock units granted on May 8, 2025 that will vest on the earlier of the one-year anniversary of the grant or DexCom’s 2026 annual meeting.

Positive

• Sales executed under a documented 10b5-1 plan, indicating pre-authorized, orderly disposition
• Clear disclosure of trade prices and ranges (prices ranged $80.29–$81.22; weighted average reported)
• Post-transaction beneficial ownership reported for The Foletta Family Trust (51,316 and 51,121 shares)

Negative

• Insider sold 2,750 shares (2,555 + 195) on 08/15/2025, which reduces the trust's holdings by that amount

Insights

Financial Analyst

TL;DR: Routine insider sales under a 10b5-1 plan; small absolute size and clearly disclosed prices and post-sale holdings.

The filing documents compliance with a pre-established 10b5-1 disposition plan and provides transaction-level transparency: executed on 08/15/2025 with prices ranging $80.29–$81.22 and a weighted average noted. Sales total 2,750 shares and reported post-transaction beneficial holdings are ~51k shares for the trust. The disclosure of newly granted unvested restricted stock units (5,731 RSUs) is material for understanding future share-based compensation dilution timing. Overall, this is a routine, transparent disclosure with limited immediate balance-sheet or operating impact.

Corporate Governance Expert

TL;DR: The insider used a documented 10b5-1 plan and the filing includes clear trustee and trust ownership disclosures.

The report affirms governance best practices by noting the existence of a 10b5-1 trading plan adopted March 13, 2025, and by identifying the reporting person’s role as trustee. The form properly discloses the nature of indirect beneficial ownership (held by The Foletta Family Trust) and the signature authority used. The itemized explanation of prices and willingness to provide trade details on request strengthens transparency. No governance red flags appear in the disclosed items.

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^*

FOLETTA MARK G

(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)

X	Director		10% Owner
	Officer (give title below)		Other (specify below)

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		2,555(1)	D	$81.0186(2)	51,316	I	by Trust
Common Stock	08/15/2025		S		195	D	$81.54	51,121	I	by Trust(3)
Common Stock								5,731(4)	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 March 13, 2025, The Foletta Family Trust DTD 1/30/2015 (the "Trust") adopted a 10b5-1 Plan. This 10b5-1 Plan allows the orderly disposition of shares owned by the Trust. The shares set forth above were sold pursuant to the 10b5-1 Plan.

2. This transaction was executed in multiple trades at prices ranging from $80.29 to $81.22. 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.

3. Shares are held by The Foletta Family Trust DTD 1/30/2015, with respect to which the reporting person is a trustee.

4. Represents unvested restricted stock units which were granted on May 8, 2025 and shall vest on the earlier of the one year anniversary of the grant date or the date of DexCom, Inc.'s 2026 Annual Meeting of Stockholders.

Remarks:

	/s/ Jereme M. Sylvain, as Attorney-in-Fact for Mark G. Foletta	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 Mark G. Foletta report on Form 4 for DXCM?

The filing reports sales of DXCM shares on 08/15/2025: 2,555 shares (weighted avg $81.0186) and 195 shares at $81.54, executed under a 10b5-1 plan.

Were the sales part of an authorized trading plan?

Yes. The Foletta Family Trust adopted a 10b5-1 plan on March 13, 2025, and the sales were made pursuant to that plan.

How many shares does the Trust report owning after the transactions?

The filing lists beneficial holdings by The Foletta Family Trust of 51,316 and 51,121 shares following the reported transactions.

Did the filing disclose any unvested awards?

Yes. It discloses 5,731 unvested restricted stock units granted on May 8, 2025, which vest the earlier of one year after grant or DexCom’s 2026 annual meeting.

What price range were the shares sold at?

Trades executed at prices ranging from $80.29 to $81.22; the filing reports a weighted average sale price for one block and a separate price for the other block.