X0306 4 2020-07-01 0 0001561550 Datadog, Inc. DDOG 0001120741 OBSTLER DAVID M C/O DATADOG, INC. 620 8TH AVENUE, 45TH FLOOR NEW YORK NY 10018 0 1 0 0 Chief Financial Officer Class A Common Stock 2020-07-01 4 S 0 1860 86.8154 D 262725 D Class A Common Stock 2020-07-01 4 S 0 7203 87.7183 D 255522 D Class A Common Stock 2020-07-01 4 S 0 6103 88.7852 D 249419 D Class A Common Stock 2020-07-01 4 S 0 4834 89.4822 D 244585 D Class A Common Stock 2020-07-02 4 C 0 300000 0.00 A 544585 D Class B Common Stock 2020-07-02 4 C 0 300000 0.00 D Class A Common Stock 300000 445000 D Class B Common Stock Class A Common 618750 618750 I By GRAT Shares sold pursuant to a 10b5-1 plan entered into on December 11, 2019. Price reported is a weighted-average sales price. The shares were sold at prices ranging from $86.23 to $87.22. 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 $87.23 to $88.20. 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 $88.27 to $89.26. 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 $89.28 to $89.76. 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. 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 are held directly by the David Obstler 2019 GRAT, of which Reporting Person is Trustee. David Obstler, by /s/ Ron A. Metgzer, Attorney-in-Fact 2020-07-06