Datadog affiliate plans $3.42M Class A stock sale

Datadog Class A common stockholders associated with the Callahan-Thernstrom Family Trust and Michael Callahan have filed a notice of intent to sell shares.

Rhea-AI Filing Summary

Datadog Class A common stockholders associated with the Callahan-Thernstrom Family Trust and Michael Callahan have filed a notice of intent to sell shares. The notice covers a planned sale of 12,500 shares of Class A Common stock through Morgan Stanley Smith Barney LLC, with an aggregate sale price of $3,420,000.00, for shares listed on NASDAQ and scheduled for 08/04/2026. These 12,500 shares were originally acquired on 04/29/2011 in a private acquisition from Datadog or an affiliate.

The disclosure also lists sales during the past three months under a 10b5-1 plan for the Callahan-Thernstrom Family Trust, including 12,500 shares sold on 07/01/2026 for $3,343,375.00, 12,500 shares sold on 06/29/2026 for $3,093,375.00, 75,000 shares sold on 06/12/2026 for $17,348,985.00, and 37,500 shares sold on 06/12/2026 for $8,706,172.50. Separately, Michael Callahan is reported to have sold 2,500 shares on 05/15/2026 for $527,387.50.

Key Figures

Planned shares to be sold: 12,500 shares Planned aggregate sale price: $3,420,000.00 Sale date for planned transaction: 08/04/2026 +5 more

8 metrics

Planned shares to be sold 12,500 shares Class A Common covered by the notice

Planned aggregate sale price $3,420,000.00 Proposed sale of 12,500 Class A shares

Sale date for planned transaction 08/04/2026 Scheduled date for the 12,500-share sale

Original acquisition date 04/29/2011 Private acquisition from issuer or an affiliate

10b5-1 sale 07/01/2026 12,500 shares for $3,343,375.00 Callahan-Thernstrom Family Trust transaction

10b5-1 sale 06/12/2026 75,000 shares for $17,348,985.00 Callahan-Thernstrom Family Trust transaction

10b5-1 sale 06/12/2026 (second) 37,500 shares for $8,706,172.50 Callahan-Thernstrom Family Trust transaction

Sale by Michael Callahan 2,500 shares for $527,387.50 Class A Common sale on 05/15/2026

Key Terms

10b5-1 Sales, Private Acquisition from Issuer or an Affiliate, Class A Common, Executive Financial Services, +1 more

5 terms

10b5-1 Sales regulatory

"10b5-1 Sales for Callahan-Thernstrom Family Trust 620 8th Avenue"

10b5-1 sales are pre-arranged stock-trading plans that let company insiders automatically buy or sell shares according to a fixed schedule or formula, even if they later learn confidential information. Think of it as setting up an automatic thermostat for trades: it creates a clear, documented path that can protect insiders from insider-trading accusations and gives investors a signal about predictable insider activity—though it can also simply be a way for insiders to diversify or raise cash.

Private Acquisition from Issuer or an Affiliate regulatory

"04/29/2011 | Private Acquisition from Issuer or an Affiliate | Issuer"

Class A Common financial

"Class A Common | Morgan Stanley Smith Barney LLC Executive Financial Services"

Executive Financial Services financial

"Morgan Stanley Smith Barney LLC Executive Financial Services 1 New York Plaza"

Securities Sold During The Past 3 Months regulatory

"144: Securities Sold During The Past 3 Months"

FAQ

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

What stock sale is disclosed for Datadog (DDOG) in this notice?

The notice reports a planned sale of 12,500 Class A Common shares of Datadog, with an aggregate sale price of $3,420,000.00, to be sold through Morgan Stanley Smith Barney LLC on 08/04/2026.

Who is associated with the Datadog (DDOG) share sale under this notice?

The notice identifies the Callahan-Thernstrom Family Trust and Michael Callahan. The trust has multiple 10b5-1 sales listed, and Michael Callahan is reported with a separate sale of 2,500 shares on 05/15/2026.

What recent 10b5-1 plan sales are disclosed for Datadog (DDOG) shares?

For the Callahan-Thernstrom Family Trust, recent 10b5-1 sales include 12,500 shares on 07/01/2026 for $3,343,375.00 and 75,000 shares on 06/12/2026 for $17,348,985.00, among other listed transactions.

When were the Datadog (DDOG) shares in the planned sale originally acquired?

The 12,500 shares covered by the planned sale were acquired on 04/29/2011 via a Private Acquisition from Issuer or an Affiliate, according to the issuer information in the notice.

Which broker is handling the planned Datadog (DDOG) stock sale?

The planned sale of 12,500 Class A Common shares with a value of $3,420,000.00 is to be executed through Morgan Stanley Smith Barney LLC Executive Financial Services, based at 1 New York Plaza, 8th Floor, New York, NY 10004.

What other Datadog (DDOG) sale is attributed directly to Michael Callahan?

Beyond the trust’s 10b5-1 transactions, Michael Callahan is listed with a sale of 2,500 Class A Common shares on 05/15/2026 for total proceeds of $527,387.50, at the same New York address as the trust.

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

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Available on EDGAR 08/04/2026 - 04:36 PM Accepted by SEC EDGAR 08/04/2026 - 04:36 PM Learn about SEC filing dates

Form 144 Filer Information	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 144 NOTICE OF PROPOSED SALE OF SECURITIES PURSUANT TO RULE 144 UNDER THE SECURITIES ACT OF 1933
FORM 144

144: Filer Information

Filer CIK	0001784030
Filer CCC	XXXXXXXX
Is this a LIVE or TEST Filing?	LIVE TEST
Submission Contact Information
Name
Phone
E-Mail Address

144: Issuer Information

Name of Issuer	Datadog, Inc.
SEC File Number	001-39051
Address of Issuer	620 8th Avenue, 45th Floor New York NEW YORK 10018
Phone	8663294466
Name of Person for Whose Account the Securities are To Be Sold	Callahan-Thernstrom Family Trust
See the definition of "person" in paragraph (a) of Rule 144. Information is to be given not only as to the person for whose account the securities are to be sold but also as to all other persons included in that definition. In addition, information shall be given as to sales by all persons whose sales are required by paragraph (e) of Rule 144 to be aggregated with sales for the account of the person filing this notice.
Relationship to Issuer	Director

144: Securities Information

Title of the Class of Securities To Be Sold	Name and Address of the Broker	Number of Shares or Other Units To Be Sold	Aggregate Market Value	Number of Shares or Other Units Outstanding	Approximate Date of Sale	Name the Securities Exchange
Class A Common	Morgan Stanley Smith Barney LLC Executive Financial Services 1 New York Plaza 8th Floor New York NY 10004	12500	3420000.00	330825798	08/04/2026	NASDAQ

Furnish the following information with respect to the acquisition of the securities to be sold and with respect to the payment of all or any part of the purchase price or other consideration therefor:

144: Securities To Be Sold

Title of the Class	Date you Acquired	Nature of Acquisition Transaction	Name of Person from Whom Acquired	Is this a Gift?	Date Donor Acquired	Amount of Securities Acquired	Date of Payment	Nature of Payment *
Class A Common	04/29/2011	Private Acquisition from Issuer or an Affiliate	Issuer			12500	04/29/2011	N/A

* If the securities were purchased and full payment therefor was not made in cash at the time of purchase, explain in the table or in a note thereto the nature of the consideration given. If the consideration consisted of any note or other obligation, or if payment was made in installments describe the arrangement and state when the note or other obligation was discharged in full or the last installment paid.

Furnish the following information as to all securities of the issuer sold during the past 3 months by the person for whose account the securities are to be sold.

144: Securities Sold During The Past 3 Months

Name and Address of Seller	Title of Securities Sold	Date of Sale	Amount of Securities Sold	Gross Proceeds
10b5-1 Sales for Callahan-Thernstrom Family Trust 620 8th Avenue, 45th Floor New York NY 10018	Class A Common	07/01/2026	12500	3343375.00
10b5-1 Sales for Callahan-Thernstrom Family Trust 620 8th Avenue, 45th Floor New York NY 10018	Class A Common	06/29/2026	12500	3093375.00
10b5-1 Sales for Callahan-Thernstrom Family Trust 620 8th Avenue, 45th Floor New York NY 10018	Class A Common	06/12/2026	75000	17348985.00
10b5-1 Sales for Callahan-Thernstrom Family Trust 620 8th Avenue, 45th Floor New York NY 10018	Class A Common	06/12/2026	37500	8706172.50
Michael Callahan 620 8th Avenue, 45th Floor New York NY 10018	Class A Common	05/15/2026	2500	527387.50

144: Remarks and Signature

Remarks
Date of Notice	08/04/2026
Date of Plan Adoption or Giving of Instruction, If Relying on Rule 10b5-1	03/13/2026
ATTENTION:
The person for whose account the securities to which this notice relates are to be sold hereby represents by signing this notice that he does not know any material adverse information in regard to the current and prospective operations of the Issuer of the securities to be sold which has not been publicly disclosed. If such person has adopted a written trading plan or given trading instructions to satisfy Rule 10b5-1 under the Exchange Act, by signing the form and indicating the date that the plan was adopted or the instruction given, that person makes such representation as of the plan adoption or instruction date.
Signature	/s/ Michael Callahan
ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)