0001595974FALSE00015959742025-09-162025-09-16

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On September 16, 2025, Magnite, Inc. (the “Company”) 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 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. A copy of the Company’s press release (the "Press Release") is furnished as Exhibit 99.1 and is incorporated herein by reference. The information contained in this Item 7.01 of this Current Report on Form 8-K, including Exhibit 99.1 hereto, shall not be deemed “filed” for purposes of Section 18 of the Securities Exchange Act of 1934, as amended (the “Exchange Act”), or otherwise subject to the liabilities of that section, nor shall it be deemed incorporated by reference in any filing made by the Company under the Securities Act of 1933, as amended or the Exchange Act, regardless of any general incorporation language in such filings, unless expressly incorporated by specific reference in such filings. The filing of this Current Report on Form 8-K shall not be deemed an admission as to the materiality of any information herein that is required to be disclosed solely by reason of Regulation FD.

The Company is also providing the following updates to the Risk Factors set forth in the Company's Annual Report on Form 10-K for the fiscal year ended December 31, 2024 and subsequently filed Quarterly Report on Form 10-Q:

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 Lawsuit") 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 Lawsuit is in its early stages, and the outcome and timing of the Google Lawsuit is uncertain and difficult to predict. The Google Lawsuit 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 Lawsuit 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 Lawsuit 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.

(d) Exhibits.

Pursuant to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized.