144 0001966411 XXXXXXXX LIVE 0001816581 Ouster, Inc. 001-39463 350 Treat Avenue San Francisco CA 94110 415-949-0108 Megan Chung Officer Common Stock ETRADE FINANCIAL CORPORATION

3 EDISON DRIVE ALPHARETTA GA 30005

18011 513493.61 57819244 09/12/2025 NASDAQ Common Stock 09/11/2025 Restricted stock awards awarded under incentive award plan Issuer N 30465 03/28/2024 Services rendered Common Stock 09/11/2025 Restricted stock units awarded under incentive award plan Issuer N 4500 03/16/2023 Services rendered Common Stock 09/11/2025 Restricted stock units awarded under incentive award plan Issuer N 225 08/10/2022 Services rendered Common Stock 09/11/2025 Restricted stock units awarded under incentive award plan Issuer N 2083 01/25/2023 Services rendered N Megan Chung

350 Treat Avenue San Francisco CA 94110

Common Stock 06/12/2025 2828 53066.29 Shares are to be sold to cover withholding taxes upon vesting of restricted stock units and restricted stock awards in a trade that will be initiated by the Issuer on the Reporting Person's behalf. The transaction dated June 12, 2025 reflects the weighted average price, with sale prices ranging from $18.7578 to $18.8634. 09/11/2025 /s/ Megan Chung