X0609 4 2026-09-14 0 0001561550 Datadog, Inc. DDOG 0001120741 OBSTLER DAVID M false C/O DATADOG, INC. 620 8TH AVENUE, 45TH FLOOR NEW YORK NY 10018 0 1 0 0 Chief Financial Officer 1 Class A Common Stock 2026-09-14 4 C 0 12000 0 A 12000 I By Trust Class A Common Stock 2026-09-14 4 S 0 798 221.2365 D 11202 I By Trust Class A Common Stock 2026-09-14 4 S 0 1624 222.1661 D 9578 I By Trust Class A Common Stock 2026-09-14 4 S 0 738 223.1165 D 8840 I By Trust Class A Common Stock 2026-09-14 4 S 0 545 224.3433 D 8295 I By Trust Class A Common Stock 2026-09-14 4 S 0 1182 225.1332 D 7113 I By Trust Class A Common Stock 2026-09-14 4 S 0 190 226.1915 D 6923 I By Trust Class A Common Stock 2026-09-14 4 S 0 169 227.7159 D 6754 I By Trust Class A Common Stock 2026-09-14 4 S 0 360 228.5859 D 6394 I By Trust Class A Common Stock 2026-09-14 4 S 0 2873 229.9209 D 3521 I By Trust Class A Common Stock 2026-09-14 4 S 0 1689 230.5094 D 1832 I By Trust Class A Common Stock 2026-09-14 4 S 0 724 231.5317 D 1108 I By Trust Class A Common Stock 2026-09-14 4 S 0 918 232.7079 D 190 I By Trust Class A Common Stock 2026-09-14 4 S 0 190 233.2997 D 0 I By Trust Class A Common Stock 2026-09-14 4 C 0 12000 0 A 12000 I By Trust Class A Common Stock 2026-09-14 4 S 0 786 221.2389 D 11214 I By Trust Class A Common Stock 2026-09-14 4 S 0 1635 222.1623 D 9579 I By Trust Class A Common Stock 2026-09-14 4 S 0 725 223.1157 D 8854 I By Trust Class A Common Stock 2026-09-14 4 S 0 525 224.3448 D 8329 I By Trust Class A Common Stock 2026-09-14 4 S 0 1169 225.1313 D 7160 I By Trust Class A Common Stock 2026-09-14 4 S 0 181 226.1915 D 6979 I By Trust Class A Common Stock 2026-09-14 4 S 0 163 227.7183 D 6816 I By Trust Class A Common Stock 2026-09-14 4 S 0 358 228.5972 D 6458 I By Trust Class A Common Stock 2026-09-14 4 S 0 2935 229.9168 D 3523 I By Trust Class A Common Stock 2026-09-14 4 S 0 1729 230.5063 D 1794 I By Trust Class A Common Stock 2026-09-14 4 S 0 713 231.5314 D 1081 I By Trust Class A Common Stock 2026-09-14 4 S 0 899 232.7071 D 182 I By Trust Class A Common Stock 2026-09-14 4 S 0 182 233.2996 D 0 I By Trust Class B Common Stock 2026-09-14 4 C 0 12000 0 D Class A Common Stock 12000 34199 I By Trust Class B Common Stock 2026-09-14 4 C 0 12000 0 D Class A Common Stock 12000 34198 I By Trust Class B Common Stock Class A Common Stock 8103 8103 D 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. Shares are held directly by Obstler Children 2019 Trust FBO the Reporting Person's child, of which the Reporting Person's spouse is Trustee. Obstler Children 2019 Trust FBO the Reporting Person's child and Obstler Children 2019 Trust FBO the Reporting Person's other child are separate trusts for the benefit of the Reporting Person's children with substantially identical terms. Shares sold pursuant to a 10b5-1 plan dated June 13, 2026. Price reported is a weighted-average sales price. The shares were sold at prices ranging from $220.67 to $221.57. 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. Price reported is a weighted-average sales price. The shares were sold at prices ranging from $221.68 to $222.65. 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. Price reported is a weighted-average sales price. The shares were sold at prices ranging from $222.70 to $223.60. 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. Price reported is a weighted-average sales price. The shares were sold at prices ranging from $223.82 to $224.81. 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. Price reported is a weighted-average sales price. The shares were sold at prices ranging from $224.82 to $225.78. 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. Price reported is a weighted-average sales price. The shares were sold at prices ranging from $225.96 to $226.54. 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. Price reported is a weighted-average sales price. The shares were sold at prices ranging from $227.095 to $228.07. 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. Price reported is a weighted-average sales price. The shares were sold at prices ranging from $228.13 to $229.12. 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. Price reported is a weighted-average sales price. The shares were sold at prices ranging from $229.13 to $230.12. 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. Price reported is a weighted-average sales price. The shares were sold at prices ranging from $230.13 to $231.11. 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. Price reported is a weighted-average sales price. The shares were sold at prices ranging from $231.13 to $232.10. 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. Price reported is a weighted-average sales price. The shares were sold at prices ranging from $232.13 to $233.12. 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. Price reported is a weighted-average sales price. The shares were sold at prices ranging from $233.13 to $233.49. 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. Shares are held directly by Obstler Children 2019 Trust FBO the Reporting Person's other child, of which the Reporting Person's spouse is Trustee. See Footnote 2. Price reported is a weighted-average sales price. The shares were sold at prices ranging from $230.13 to $231.10. 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. Due to the 30 line limitation in Table I, this report is being filed across two forms. This is the second of two filings. /s/ Kerry Acocella, Attorney-in-Fact 2026-09-16