X0609 4 2026-09-01 0 0001561550 Datadog, Inc. DDOG 0001783984 Le-Quoc Alexis false C/O DATADOG, INC. 620 8TH AVENUE, 45TH FLOOR NEW YORK NY 10018 1 1 0 0 Chief Technology Officer 1 Class A Common Stock 2026-09-01 4 C 0 43224 0 A 553029 D Class A Common Stock 2026-09-01 4 C 0 10688 0 A 563717 D Class A Common Stock 2026-09-01 4 S 0 11367 223.586 D 552350 D Class A Common Stock 2026-09-01 4 S 0 7604 224.6085 D 544746 D Class A Common Stock 2026-09-01 4 S 0 9134 225.621 D 535612 D Class A Common Stock 2026-09-01 4 S 0 2991 226.5648 D 532621 D Class A Common Stock 2026-09-01 4 S 0 4177 227.7164 D 528444 D Class A Common Stock 2026-09-01 4 S 0 5339 228.6274 D 523105 D Class A Common Stock 2026-09-01 4 S 0 5500 229.6294 D 517605 D Class A Common Stock 2026-09-01 4 S 0 2500 230.3424 D 515105 D Class A Common Stock 2026-09-01 4 S 0 600 231.5444 D 514505 D Class A Common Stock 2026-09-01 4 S 0 1100 233.2843 D 513405 D Class A Common Stock 2026-09-01 4 S 0 1800 234.0889 D 511605 D Class A Common Stock 2026-09-01 4 S 0 1400 235.0529 D 510205 D Class A Common Stock 2026-09-01 4 S 0 400 236.05 D 509805 D Class A Common Stock 169 I By Trust Stock Option (Right to Buy) 10.74 2026-09-01 4 M 0 18750 0 D 2029-07-19 Class B Common Stock 18750 131250 D Class B Common Stock 2026-09-01 4 M 0 18750 10.74 A Class A Common Stock 18750 2257166 D Class B Common Stock 2026-09-01 4 C 0 53912 0 D Class A Common Stock 53912 2203254 D Class B Common Stock Class A Common Stock 6146835 6146835 I By Trust 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 sold pursuant to a 10b5-1 plan dated June 13, 2025. Price reported is a weighted-average sales price. The shares were sold at prices ranging from $223.11 to $224.10. 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 $224.11 to $225.10. 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 $225.12 to $226.11. 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 $226.15 to $227.13. 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 $227.18 to $228.175. 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 $228.18 to $229.13. 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 $229.18 to $230.14. 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 $230.18 to $230.68. 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 $231.35 to $231.89. 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 $232.69 to $233.63. 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 $233.69 to $234.58. 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 $234.84 to $235.78. 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 $236.05 to $236.05. 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 by the Alexis Le-Quoc Revocable Trust. Option is fully vested and exercisable. /s/ Kerry Acocella, Attorney-in-Fact 2026-09-03