MONOLITHIC POWER SYSTEMS INC

We are a party to actions and proceedings in the ordinary course of business, including challenges to the enforceability or validity of our intellectual property, claims that our products infringe on the intellectual property rights of others, and employment matters. We are also subject to litigation initiated by our stockholders. These proceedings often involve complex questions of fact and law and* *may require the expenditure of significant funds and the diversion of other resources to prosecute and defend. We defend ourselves vigorously against any such claims. Based on current information and management assessment, we do not believe that a material loss from known matters is probable as of December 31, 2025.

On February 4, 2025, a class action lawsuit was filed against us and certain of our executives. The lawsuit is captioned Waterford Twp. Gen. Emps. Ret. Sys. v. Monolithic Power Systems, Inc., et al., No. 25-cv-220 (W.D. Wash.) (the “Securities Action”) and alleges that we violated Sections 10(b) and 20(a) of the Securities Exchange Act of 1934, as amended, and Rule 10b-5 promulgated thereunder, by making material misstatements or omissions relating to our business. We believe the lawsuit is meritless and currently intend to defend against it vigorously. Related to the Securities Action, two shareholder derivative suits were also filed, against current – and one former – director, and certain executives, alleging breaches of their fiduciary duties. The shareholder derivative suits have been consolidated under the caption Miller v. Hsing, et al., No. 25-cv-527 (W.D. Wash.), filed on March 26, 2025 (the “Derivative Litigation”). The Securities Action and Derivative Litigation seek unspecified amounts of damages and/or attorneys’ fees and other relief. The Derivative Litigation is stayed pending developments in the Securities Action.