Datadog trust plans $690K stock sale under Rule 144

A trust affiliated with a Datadog executive filed a Rule 144 notice to sell 3,000 Class A shares, alongside recent disclosed 10b5-1 plan sales.

Rhea-AI Filing Summary

Datadog, Inc. (DDOG) received a Rule 144 notice for a proposed sale of 3,000 shares of Class A common stock for the account of the David Obstler Children 2019 Trust FBO Alison Obstler.

The shares were acquired on March 5, 2019 through previously exercised stock options and are to be sold for cash through Morgan Stanley Smith Barney LLC Executive Financial Services$689,760 for these shares and notes that Datadog had 334,904,614 shares outstanding as of September 21, 2026; this is a baseline figure, not the amount being sold. Recent 10b5-1 plan sales by David Obstler and related trusts over the past three months are also disclosed.

Key Figures

Shares to be sold under Rule 144: 3,000 shares Aggregate market value of shares to be sold: $689,760.00 Shares outstanding: 334,904,614 shares +4 more

7 metrics

Shares to be sold under Rule 144 3,000 shares Class A common stock for David Obstler Children 2019 Trust FBO Alison Obstler

Aggregate market value of shares to be sold $689,760.00 Estimated value of the 3,000 Class A shares covered by the notice

Shares outstanding 334,904,614 shares Datadog Class A common stock outstanding as of September 21, 2026

Acquisition date of shares March 5, 2019 Date the 3,000 shares were acquired via previously exercised stock options

Recent 10b5-1 sale by David Obstler 40,000 shares for $9,098,879.00 Class A common stock sold on September 14, 2026

Recent 10b5-1 sale by Alison Obstler trust 12,000 shares for $2,729,663.70 Class A common stock sold on September 14, 2026

Recent non-plan sale by David Obstler 16,524 shares for $3,518,027.35 Class A common stock sold on September 2, 2026

Key Terms

Rule 144, Form S-8, 10b5-1, Previously Exercised Stock Options

4 terms

Rule 144 regulatory

"See the definition of "person" in paragraph (a) of Rule 144."

Rule 144 is a U.S. securities regulation that sets conditions under which restricted or insider-held shares can be legally resold to the public, such as required holding periods, availability of public information, limits on how much can be sold at once, and certain filing requirements. For investors it matters because it determines when previously locked-up shares can enter the market — like a release valve that can increase supply, affect share price, and signal insider intent.

Form S-8 regulatory

"were registered on Form S-8."

A Form S-8 is a U.S. Securities and Exchange Commission registration that lets a public company set aside shares for employee benefit plans and stock-based compensation. Think of it as opening a dedicated account that authorizes the company to issue or reserve stock for workers and directors; it matters to investors because it enables share dilution when those awards are granted or exercised and signals how management is compensated and incentivized.

10b5-1 regulatory

"10b5-1 Sales for DAVID OBSTLER"

A 10b5-1 plan is a pre-set schedule that lets company insiders buy or sell shares according to written instructions made when they do not possess material, nonpublic information. Think of it as a timed automatic payment for stock trades: it helps insiders avoid accusations of trading on secret information and gives outside investors a clearer signal about whether sales are routine or potentially informative about the company’s prospects.

Previously Exercised Stock Options financial

"Previously Exercised Stock Options | Issuer"

FAQ

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

What does the Form 144 filing disclose for Datadog (DDOG)?

It discloses a planned Rule 144 sale of 3,000 Datadog Class A shares for the David Obstler Children 2019 Trust FBO Alison Obstler, with an indicated market value of about $689,760, plus recent 10b5-1 plan sales by David Obstler and related trusts.

Who is selling Datadog (DDOG) shares under this Form 144?

The notice is filed for the David Obstler Children 2019 Trust FBO Alison Obstler. The broker is Morgan Stanley Smith Barney LLC Executive Financial Services, and the securities are Datadog Class A common stock to be sold for cash.

How many Datadog (DDOG) shares are covered by this Rule 144 notice and what is their value?

The filing covers 3,000 shares of Datadog Class A common stock, with an aggregate market value shown as about $689,760. These shares were acquired through previously exercised stock options on March 5, 2019.

What recent Datadog (DDOG) share sales are reported over the past three months?

Reported sales include 40,000 shares for about $9,098,879 and 16,524 shares for about $3,518,027.35 by David Obstler, plus 12,000 shares for about $2,729,663.70 each by two related 2019 trusts.

How many Datadog (DDOG) shares were outstanding at the time of this notice?

The filing states that 334,904,614 Datadog shares were outstanding as of September 21, 2026. This outstanding share count is provided for context and is separate from the 3,000 shares covered by the Rule 144 notice.

How were the Datadog (DDOG) shares in this Form 144 originally acquired?

The 3,000 Datadog Class A shares were acquired on March 5, 2019 through previously exercised stock options, and the filing notes that securities to be sold, acquired through RSU/PSU or upon option exercise, were registered on Form S-8.

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

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Available on EDGAR 09/21/2026 - 04:36 PM Accepted by SEC EDGAR 09/21/2026 - 04:35 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	0001120741
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	David Obstler Children 2019 Trust FBO Alison Obstler
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	Officer

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	3000	689760.00	334904614	09/21/2026	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 *
Common	03/05/2019	Previously Exercised Stock Options	Issuer			3000	03/05/2019	Cash

* 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 DAVID OBSTLER 620 8th Avenue, 45th Floor New York NY 10018	Class A Common	09/14/2026	40000	9098879.00
10b5-1 Sales for DAVID OBSTLER CHILDREN 2019 TRUST FBO ALISON OBSTLER 620 8th Avenue, 45th Floor New York NY 10018	Class A Common	09/14/2026	12000	2729663.70
10b5-1 Sales for DAVID OBSTLER CHILDREN 2019 TRUST FBO ANDREW OBSTLER 620 8th Avenue, 45th Floor New York NY 10018	Class A Common	09/14/2026	12000	2729663.70
DAVID OBSTLER 620 8th Avenue, 45th Floor New York NY 10018	Class A Common	09/02/2026	16524	3518027.35

144: Remarks and Signature

Remarks	Securities to be sold, acquired through RSU/PSU or upon option exercise, were registered on Form S-8.
Date of Notice	09/21/2026
Date of Plan Adoption or Giving of Instruction, If Relying on Rule 10b5-1	06/13/2026
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/ Thea Obstler
ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)