144 0002020217 XXXXXXXX LIVE 0001943896 RUBRIK, INC. 001-42028 3495 DEER CREEK ROAD PALO ALTO CA 94304 844-478-2745 Brian K. McCarthy Officer Class A Common Stock Morgan Stanley Smith Barney LLC Executive Financial Services

1 New York Plaza 39th Floor New York NY 10004

4815 442980.00 123563326 06/17/2025 NYSE Class A Common Stock 06/17/2025 Restricted Stock Units vesting under registered plan Issuer N 4815 06/17/2025 Compensation N Brian K McCarthy

3495 Deer Creek Road Palo Alto CA 94304

Class A Common Stock 03/21/2025 85001 5953470 Brian K McCarthy

3495 Deer Creek Road Palo Alto CA 94304

Class A Common Stock 04/01/2025 25000 1502392.30 Brian K. McCarthy

3495 Deer Creek Road Palo Alto CA 94304

Class A Common Stock 05/01/2025 25000 1786055.60 Brian K McCarthy

3495 Deer Creek Road Palo Alto CA 94304

Class A Common Stock 06/02/2025 25000 2455098.25 Brian K McCarthy

3495 Deer Creek Road Palo Alto CA 94304

Class A Common Stock 06/05/2025 25000 2504500.00 This is a sell-to-cover transaction for taxes owed related to recent vestings of stock unit awards granted by the issuer. 06/17/2025 /s/ Larry Guo, Attorney-in-Fact