144 0001783984 XXXXXXXX LIVE 0001561550 Datadog, Inc. 001-39051 620 8th Avenue, 45th Floor New York NY 10018 8663294466 ALEXIS T LEQUOC Director Officer Class A Common Morgan Stanley Smith Barney LLC Executive Financial Services

1 New York Plaza 8th Floor New York NY 10004

32300 3887628.00 328274648 04/06/2026 NASDAQ Class A Common 04/06/2026 Exercise of Stock Options Issuer N 10688 04/06/2026 Cash Class A Common 12/06/2023 Previously Exercised Stock Options Issuer N 21612 12/06/2023 Cash N 10b5-1 Sales for ALEXIS T LEQUOC

620 8th Avenue, 45th Floor New York NY 10018

Class A Common 03/23/2026 32418 4141418.95 10b5-1 Sales for ALEXIS T LEQUOC

620 8th Avenue, 45th Floor New York NY 10018

Class A Common 03/10/2026 43224 5424382.91 10b5-1 Sales for ALEXIS T LEQUOC

620 8th Avenue, 45th Floor New York NY 10018

Class A Common 03/10/2026 10688 1341287.35 ALEXIS T LEQUOC

620 8th Avenue, 45th Floor New York NY 10018

Class A Common 03/02/2026 53541 5918202.62 10b5-1 Sales for ALEXIS T LEQUOC

620 8th Avenue, 45th Floor New York NY 10018

Class A Common 02/23/2026 21612 2266660.08 10b5-1 Sales for ALEXIS T LEQUOC

620 8th Avenue, 45th Floor New York NY 10018

Class A Common 02/11/2026 32418 4110310.64 10b5-1 Sales for ALEXIS T LEQUOC

620 8th Avenue, 45th Floor New York NY 10018

Class A Common 02/11/2026 10688 1355142.21 10b5-1 Sales for ALEXIS T LEQUOC

620 8th Avenue, 45th Floor New York NY 10018

Class A Common 01/28/2026 32418 4570510.08 The securities to be sold were acquired upon the previous exercise of stock options during the period of 12/06/2023 through 10/14/2024. Securities to be sold, acquired through RSU/PSU or upon option exercise, were registered on Form S-8. 04/06/2026 06/13/2025 /s/ Alexis T. Le-Quoc