X0508 4 2026-02-23 0 0001561550 Datadog, Inc. DDOG 0001783984 Le-Quoc Alexis 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 2026-02-23 4 C 0 21612 0 A 512410 D Class A Common Stock 2026-02-23 4 S 0 7712 102.0909 D 504698 D Class A Common Stock 2026-02-23 4 S 0 1300 103.0998 D 503398 D Class A Common Stock 2026-02-23 4 S 0 2800 104.0233 D 500598 D Class A Common Stock 2026-02-23 4 S 0 800 105.235 D 499798 D Class A Common Stock 2026-02-23 4 S 0 3900 106.2876 D 495898 D Class A Common Stock 2026-02-23 4 S 0 1100 107.336 D 494798 D Class A Common Stock 2026-02-23 4 S 0 1600 108.4381 D 493198 D Class A Common Stock 2026-02-23 4 S 0 1600 109.4182 D 491598 D Class A Common Stock 2026-02-23 4 S 0 400 110.425 D 491198 D Class A Common Stock 2026-02-23 4 S 0 400 111.2993 D 490798 D Class A Common Stock 169 I By Trust Class B Common Stock 2026-02-23 4 C 0 21612 0 D Class A Common Stock 21612 2563814 D Stock Option (Right to Buy) 10.74 2026-02-23 4 M 0 112500 0 D 2029-07-19 Class B Common Stock 112500 262500 D Class B Common Stock 2026-02-23 4 M 0 112500 10.74 A Class A Common Stock 112500 2676314 D Class B Common Stock Class A Common Stock 6203835 6203835 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 $101.58 to $102.56. 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 $102.58 to $103.57. 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 $103.58 to $104.52. 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 $104.83 to $105.76. 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 $105.87 to $106.85. 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 $106.88 to $107.84. 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 $107.98 to $108.97. 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 $108.98 to $109.9. 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 $110.05 to $110.97. 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 $111.06 to $111.45. 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. Shares are held by the Alexis Le-Quoc Revocable Trust. Option is fully vested and exercisable. /s/ Kerry Acocella, Attorney-in-Fact 2026-02-25