[Form 4] Datadog, Inc. Insider Trading Activity

Rhea-AI Filing Summary

Datadog, Inc. (DDOG) reporting person Michael James Callahan, a director and trustee of The Callahan-Thernstrom Family Trust, executed transactions on 10/06/2025. The form shows an acquisition of 91,667 shares of Class B common stock (convertible into Class A) with a $0 per-share price and simultaneous sales of 91,667 shares of Class A common stock under a 10b5-1 plan.

The sold shares were reported at a weighted-average sales price of $157.6024 (range $157.47 to $158.43). After the reported transactions, the filing shows 12,496 shares of Class A common stock beneficially owned indirectly by the trust; Table II also reports an indirect holding of 276,375 Class A shares after conversion mechanics are applied.

Positive

• Sales executed pursuant to a documented 10b5-1 plan dated 12/12/2024, providing an affirmative defense for timing
• Weighted-average sale price disclosed as $157.6024, with price range provided ($157.47–$158.43)

Negative

• Reported reduction of indirect Class A holdings by 91,667 shares from the trust after the sales
• Form shows lower immediate indirect Class A ownership of 12,496 shares following the reported transactions

Insights

Corporate Governance Analyst

Insider used a 10b5-1 plan to sell shares and also recorded convertible Class B shares held in trust.

The reporting person, identified as a director and trustee, sold 91,667 Class A shares under a documented 10b5-1 plan dated 12/12/2024, with a weighted-average price of $157.6024. The form also records acquisition/holding of 91,667 Class B shares that convert into Class A shares, which affects total indirect holdings.

This filing clarifies ownership structure: shares are held indirectly by a family trust and conversion terms allow Class B to become Class A. Monitor subsequent Form 4s for any additional sales or conversions that change the trust's reported indirect holdings within the next few reporting cycles.

Equity Transactions Specialist

Sale details are explicit: 91,667 shares sold at a weighted-average of $157.6024.

The sale tranche lists prices ranging from $157.47 to $158.43 and the filer offers to provide per-price breakdowns on request. The use of a 10b5-1 plan is documented, which explains the timing and execution of the sales.

Investors tracking insider liquidity should note the exact share counts and the plan date 12/12/2024. Look for disclosure of any further planned sales under the same plan or amendments in filings filed over the coming months.

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^*

Callahan Michael James

(Last) (First) (Middle)

C/O DATADOG, INC.

620 8TH AVENUE, 45TH FLOOR

(Street)

NEW YORK NY 10018

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Datadog, Inc. [ DDOG ]

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)
10/06/2025

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
Class A Common Stock	10/06/2025		C(1)		91,667	A	$0	104,163	I	By Trust(2)
Class A Common Stock	10/06/2025		S(3)		91,667	D	$157.6024(4)	12,496	I	By Trust(2)
Class A Common Stock								19,612	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
Class B Common Stock	(1)	10/06/2025		C			91,667	(1)	(1)	Class A Common Stock	91,667	$0	276,375	I	By Trust(2)

Explanation of Responses:

1. Each share of Class B Common Stock is convertible at any time at the option of the Reporting Person into one share of Class A Common Stock and has no expiration date. Each share of Class B Common Stock will convert automatically into one share of Class A Common Stock upon the earliest of: (i) any transfer, whether or not for value, except for certain "Permitted Transfers" as defined in the Issuer's amended and restated certificate of incorporation, (ii) the death of the Reporting Person in the case of shares held directly or in a trustee capacity, and (iii) the tenth anniversary of the Issuer's initial public offering of its Class A Common Stock.

2. The Shares are held by The Callahan-Thernstrom Family Trust, of which Reporting Person is Trustee

3. Shares sold pursuant to a 10b5-1 plan dated December 12, 2024.

4. Price reported is a weighted-average sales price. The shares were sold at prices ranging from $157.4700 to $158.4300. The Reporting Person will provide upon request to the SEC, the Issuer or security holder of the Issuer, full information regarding the number of shares sold at each separate price.

Remarks:

	/s/ Kerry Acocella, Attorney-in-Fact	10/08/2025
	** 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 Datadog director Michael Callahan report on Form 4 (DDOG)?

He reported acquiring 91,667 Class B shares and selling 91,667 Class A shares on 10/06/2025, with sales executed under a 10b5-1 plan.

At what price were the DDOG shares sold in the Form 4?

The shares were sold at a weighted-average price of $157.6024, with individual sales ranging from $157.47 to $158.43.

How many DDOG shares does the trust hold after the reported transactions?

The filing shows 12,496 Class A shares beneficially owned indirectly by the trust after the reported transactions; Table II also indicates an indirect holding of 276,375 Class A shares when conversion mechanics are applied.

Was the sale under a pre-arranged plan?

Yes, the sales were made pursuant to a 10b5-1 plan dated 12/12/2024, as indicated in the filing.

Who holds the reported shares for Michael Callahan?

The shares are held by The Callahan-Thernstrom Family Trust, of which he is the trustee; the filing notes the holdings are indirect.