Exhibit 99.1 Magnite Reports First Quarter 2024 Results Total Revenue Grows 15% & Contribution ex-TAC(1) Grows 12% Year-Over-Year Contribution ex-TAC(1) from CTV Grows 18% Year-Over-Year NEW YORK, New York – May 8, 2024 – Magnite (NASDAQ: MGNI), the world's largest independent sell-side advertising company, today reported its results of operations for the quarter ended March 31, 2024. Q1 2024 Highlights: • Revenue of $149.3 million, up 15$130.6 million, up 12% ye ...