X0306 4 2021-09-08 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 President & CTO Class A Common Stock 2021-09-08 4 C 0 257520 0.00 A 257520 I By Trust Class A Common Stock 2021-09-08 4 S 0 19996 133.5594 D 237524 I By Trust Class A Common Stock 2021-09-08 4 S 0 32866 134.5657 D 204658 I By Trust Class A Common Stock 2021-09-08 4 S 0 47739 135.4997 D 156919 I By Trust Class A Common Stock 2021-09-08 4 S 0 4507 136.441 D 152412 I By Trust Class A Common Stock 2021-09-08 4 S 0 8375 137.6381 D 144037 I By Trust Class A Common Stock 2021-09-08 4 S 0 41282 138.7875 D 102755 I By Trust Class A Common Stock 2021-09-08 4 S 0 75206 139.5296 D 27549 I By Trust Class A Common Stock 2021-09-08 4 S 0 27549 140.4043 D 0 I By Trust Class A Common Stock 620 I By GRAT Class A Common Stock 174764 D Class B Common Stock 2021-09-08 4 C 0 257520 0.00 D Class A Common Stock 257520 9516343 I By Trust Class B Common Stock Class A Common Stock 2782108 I By GRAT Each share of Class B Common Stock is convertible into an equal number of shares of Class A Common Stock at any time, at the holder's election, 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 nine-month anniversary of 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 by the Alexis Le-Quoc Revocable Trust. Shares sold pursuant to a 10b5-1 plan entered into on June 14, 2021. Price reported is a weighted-average sales price. The shares were sold at prices ranging from $133.07 to $134.06. 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 $134.07 to $135.06. 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 $135.07 to $136.06. 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 $136.07 to $137.00. 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 $137.07 to $138.06. 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 $138.09 to $139.08 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 $139.09 to $140.08. 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 $140.09 to $141.04. 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 2016 GRAT. Alexis Le-Quoc, by /s/ Ron A. Metzger, Attorney-in-Fact 2021-09-10