X0306 4 2022-06-07 0 0001595974 MAGNITE, INC. MGNI 0001575492 PEARSON DAVID T. C/O MAGNITE, INC. 1250 BROADWAY, 15TH FLOOR NEW YORK NY 10001 1 0 0 0 Common Stock 2022-06-07 4 A 0 16489 0.00 A 48911 D Represents restricted stock units that vest in full on the earliest of (i) June 7, 2023, (ii) the date of the 2023 annual meeting of the Issuer's stockholders, or (iii) a change of control of the Issuer. Granted as compensation for services. /s/ Aaron Saltz, attorney-in-fact 2022-06-09