X0306 4 2022-01-31 0 0001656634 Gritstone bio, Inc. GRTS 0001754280 Jooss Karin C/O GRITSTONE BIO, INC. 5959 HORTON STREET, SUITE 300 EMERYVILLE CA 94608 0 1 0 0 See Remarks Common Stock 2022-01-31 4 A 0 27600 0 A 377384 D Stock Option (Right to Buy) 5.46 2022-01-31 4 A 0 165600 0 A 2032-01-30 Common Stock 165600 165600 D Represents Restricted Stock Units ("RSUs") which vest on the first anniversary of the grant date. Each RSU represents a contingent right to receive one share of common stock of the Issuer. Includes 41,550 Restricted Stock Units which are subject to vesting. One forty-eighth (1/48th) of the shares initially subject to the option will vest on each monthly anniversary measured from January 31, 2022 (the "Vesting Commencement Date"), so that 100% of the shares subject to the option will be fully vested and exercisable as of the fourth anniversary of the Vesting Commencement Date, subject to the Reporting Person's continued service through each vesting date. Executive Vice President and Head of Research and Development /s/ Rahsaan Thompson, Attorney-in-Fact for Karin Jooss 2022-04-20