MAGNITE, INC.

Investing in our common stock involves a high degree of risk. We describe risks associated with our business in Part I, Item 1A: "Risk Factors" of our Annual Report on Form 10-K for the year ended December 31, 2024 and in Part II, Item 1A "Risk Factors" of our Quarterly Report on Form 10-Q for the period ended March 31, 2025 (the "Risk Factors"). Each of the risks described in our Risk Factors may be relevant to decisions regarding an investment in or ownership of our stock. The occurrence of any such risks could have a significant adverse effect on our reputation, business, financial condition, revenue, results of operations, growth, or ability to accomplish our strategic objectives, and could cause the trading price of our common stock to decline. You should carefully consider such risks and the other information contained in this report, including our condensed consolidated financial statements and related notes and Management's Discussion and Analysis of Financial Condition and Results of Operations, before making investment decisions related to our common stock.

The following risk factor supplements the Risk Factors contained in our Annual Report on Form 10-K for the year ended December 31, 2024 and in our Quarterly Report on Form 10-Q for the period ended March 31, 2025. Except as set forth below, there are no additional material changes to the Risk Factors of which we are currently aware; but our Risk Factors cannot anticipate and fully address all possible risks of investing in our common stock, the risks of investing in our common stock may change over time, and additional risks and uncertainties that we are not aware of, or that we do not consider to be material, may emerge. In addition, the economic impact of macroeconomic challenges, such as inflation, global conflict, capital market disruptions and the instability of financial institutions, the risk of a recession, and other macroeconomic factors may amplify many of the risks described in our risk factors. Accordingly, you are advised to consider additional sources of information and exercise your own judgment in addition to the information we provide.

Our litigation with Google LLC presents potential risks that could adversely affect our business, results of operations and financial condition.

On September 16, 2025, we filed a lawsuit in the U.S. District Court for the Eastern District of Virginia against Google LLC ("Google") seeking financial damages and other remedies (the "Google Action") in light of the U.S. District Court’s ruling that Google had engaged in unlawful anticompetitive practices with respect to certain ad tech markets. Google is a significant participant in the digital advertising ecosystem and both a major partner and competitor to Magnite and a significant portion of our revenue is generated through our relationship with Google. The Google Action is in its early stages, and the outcome and timing of the Google Action is uncertain and difficult to predict. The Google Action presents several risks to our business, including the potential for retaliatory actions by Google. Any such actions could disrupt our ability to serve our customers and partners, reduce our revenue, and harm our relationships with publishers and advertisers. The Google Action may be costly, protracted, and divert management's attention and resources from our business operations. Any damages awarded may not be commensurate with our expectations, and we may not receive any monetary damages at all. The existence of the Google Action and any potential retaliatory measures could also negatively affect our reputation and our ability to compete, potentially causing our business, financial condition, and results of operations to be materially and adversely affected.