X0609 4 2026-09-11 0 0001561550 Datadog, Inc. DDOG 0001903980 Walters Sean Michael false C/O DATADOG, INC. 620 8TH AVENUE, 45TH FLOOR NEW YORK NY 10018 0 1 0 0 Chief Revenue Officer 1 Class A Common Stock 2026-09-11 4 S 0 800 219.6846 D 244045 D Class A Common Stock 2026-09-11 4 S 0 5824 220.6722 D 238221 D Class A Common Stock 2026-09-11 4 S 0 4286 221.4015 D 233935 D Class A Common Stock 2026-09-11 4 S 0 500 222.3125 D 233435 D Class A Common Stock 2026-09-11 4 S 0 300 224.4533 D 233135 D Class A Common Stock 8 I By Son Shares sold pursuant to a 10b5-1 plan dated December 12, 2025. Price reported is a weighted-average sales price. The shares were sold at prices ranging from $219.13 to $220.08. 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 $220.18 to $221.17. 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 $221.19 to $221.89. 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 $222.20 to $222.45. 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 $224.13 to $224.86. 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. /s/ Kerry Acocella, Attorney-in-Fact 2026-09-15