Dexcom director sells 8,089 shares at about $84

Dexcom director Nicholas Augustinos disclosed pre-planned trust sales totaling 8,089 shares and retains 5,575 unvested RSUs.

Rhea-AI Filing Summary

DEXCOM INC (DXCM) director Nicholas Augustinos reported two insider sales of Dexcom common stock that were executed indirectly through the Kirschner/Augustinos Revocable Trust, for which he is a trustee. On September 15, 2026, the trust sold 6,539 shares at $84.04 per share, and on September 14, 2026 it sold 1,550 shares at $84.02 per share. A Rule 10b5-1 trading plan adopted on June 10, 2026 governs these transactions. Separately, Augustinos holds 5,575 unvested restricted stock units directly, granted on May 28, 2026, which will vest on the earlier of the one-year anniversary of the grant date or Dexcom’s 2027 annual meeting of stockholders.

Insider Trade Summary 10b5-1

Net Seller: 8,089 shares

Net Sell 3 txns

Insider AUGUSTINOS NICHOLAS

Role Director

Sold 8,089 shs ($680K)

Type	Security	Shares	Price	Value
Sale	Common Stock F1, F2	6,539	$84.04	$550K
Sale	Common Stock F1, F2	1,550	$84.02	$130K
holding	Common Stock F3	--	--	--

Holdings After Transaction: Common Stock — 29,293 shares (Indirect, by Trust); Common Stock — 5,575 shares (Direct)

Footnotes (3)

1. F1. On June 10, 2026, Mr. Augustinos adopted a 10b5-1 Plan. This 10b5-1 Plan allows the orderly disposition of shares owned by Mr. Augustinos. The shares set forth above were sold pursuant to the 10b5-1 Plan.
2. F2. Shares are held by the Kirschner/Augustinos Revocable Trust, with respect to which the Reporting Person is a trustee.
3. F3. Represents unvested restricted stock units which were granted on May 28, 2026 and will vest on the earlier of the one year anniversary of the grant date or the date of DexCom, Inc.'s 2027 Annual Meeting of Stockholders.

Key Figures

Shares sold September 15, 2026: 6,539 shares Sale price September 15, 2026: $84.04 per share Shares sold September 14, 2026: 1,550 shares +4 more

7 metrics

Shares sold September 15, 2026 6,539 shares Indirect sale of Dexcom common stock by trust

Sale price September 15, 2026 $84.04 per share Indirect sale of 6,539 shares of common stock

Shares sold September 14, 2026 1,550 shares Indirect sale of Dexcom common stock by trust

Sale price September 14, 2026 $84.02 per share Indirect sale of 1,550 shares of common stock

Total shares sold under plan 8,089 shares Combined September 14–15, 2026 trust sales

Rule 10b5-1 Plan adoption date June 10, 2026 Plan governing the reported share sales

Unvested restricted stock units 5,575 RSUs Dexcom equity award granted May 28, 2026

Key Terms

Rule 10b5-1 Plan, Revocable Trust, unvested restricted stock units

3 terms

Rule 10b5-1 Plan regulatory

"On June 10, 2026, Mr. Augustinos adopted a 10b5-1 Plan."

A Rule 10b5-1 plan is a prearranged, written schedule that lets corporate insiders buy or sell company stock at set times or amounts, even if they later learn material nonpublic information. Think of it like setting an automatic thermostat for trades: it creates a clear record that trades were planned in advance, reducing the risk of insider-trading accusations and helping investors trust that insider transactions are routine rather than based on secret information.

Revocable Trust financial

"Shares are held by the Kirschner/Augustinos Revocable Trust"

A revocable trust is a legal arrangement where the person who creates it keeps control and can change or cancel the trust at any time, while naming who will manage and receive the assets later. Think of it like a flexible folder for your investments and property that can be relabeled or reworked as circumstances change; it matters to investors because it determines how ownership is recorded, how easily assets transfer on incapacity or death, and whether holdings bypass public probate proceedings.

unvested restricted stock units financial

"Represents unvested restricted stock units which were granted on May 28, 2026"

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What insider transactions did DXCM director Nicholas Augustinos report?

He reported two indirect sales of Dexcom common stock: 6,539 shares sold on September 15, 2026 at $84.04 per share and 1,550 shares sold on September 14, 2026 at $84.02 per share, all through a revocable trust where he serves as trustee.

Were the recent DXCM insider sales by Augustinos under a Rule 10b5-1 plan?

Yes. A footnote states that on June 10, 2026, Nicholas Augustinos adopted a Rule 10b5-1 Plan, and the shares sold on September 14 and 15, 2026 were disposed of pursuant to this pre-arranged trading plan.

How many DXCM shares did the trust associated with Augustinos sell?

The Kirschner/Augustinos Revocable Trust, with Nicholas Augustinos as trustee, sold a total of 8,089 shares of Dexcom common stock, consisting of 6,539 shares on September 15, 2026 and 1,550 shares on September 14, 2026.

Does Augustinos still hold Dexcom equity after these Form 4 transactions?

Yes. He holds 5,575 unvested restricted stock units of Dexcom common stock directly. These RSUs were granted on May 28, 2026 and will vest on the earlier of the one-year anniversary of that date or Dexcom’s 2027 annual meeting of stockholders.

Are the reported DXCM insider sales direct or indirect holdings?

The reported sales involve indirect ownership. The shares are held by the Kirschner/Augustinos Revocable Trust, and the filing notes that Nicholas Augustinos is a trustee of this trust, which carried out the sales.

AI-generated analysis. How Rhea-AI works. Not financial advice.

Form 4 Insider Transactions: What Each Field Means →

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Available on EDGAR 09/16/2026 - 04:26 PM Accepted by SEC EDGAR 09/16/2026 - 04:26 PM Learn about SEC filing dates

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^*

AUGUSTINOS NICHOLAS

(Last) (First) (Middle)

6340 SEQUENCE DRIVE

(Street)

SAN DIEGO CALIFORNIA 92121

(City) (State) (Zip)

UNITED STATES

(Country)

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)

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
09/14/2026

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

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

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

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	09/14/2026		S		1,550(1)	D	$84.02	35,832	I	by Trust(2)
Common Stock	09/15/2026		S		6,539(1)	D	$84.04	29,293	I	by Trust(2)
Common Stock								5,575(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. On June 10, 2026, Mr. Augustinos adopted a 10b5-1 Plan. This 10b5-1 Plan allows the orderly disposition of shares owned by Mr. Augustinos. The shares set forth above were sold pursuant to the 10b5-1 Plan.

2. Shares are held by the Kirschner/Augustinos Revocable Trust, with respect to which the Reporting Person is a trustee.

3. Represents unvested restricted stock units which were granted on May 28, 2026 and will vest on the earlier of the one year anniversary of the grant date or the date of DexCom, Inc.'s 2027 Annual Meeting of Stockholders.

Remarks:

	/s/ Jereme M. Sylvain, as Attorney-in-Fact for Nicholas Augustinos	09/16/2026
	** 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.
* Form 4: SEC 1474 (03-26)