X0306 4 2020-05-20 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 2020-05-20 4 S 0 13343 70.2677 D 311242 D Class A Common Stock 2020-05-20 4 S 0 6382 70.8374 D 304860 D Class A Common Stock 2020-05-20 4 S 0 275 71.7145 D 304585 D Class B Common Stock Class A Common Stock 756353 D Class B Common Stock Class A Common Stock 607397 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 $69.63 to $70.62. 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. Includes 1,073 shares acquired under the Datadog, Inc. 2019 Employee Stock Purchase Plan on May 15, 2020. Price reported is a weighted-average sales price. The shares were sold at prices ranging from $70.63 to $71.44. 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 $71.66 to $71.78. 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. 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. Includes 11,353 shares previously held by the David Obstler 2019 GRAT which were distributed to the Reporting Person on May 15, 2020 in an exempt annuity payment and are now owned directly. 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 2020-05-22