Monte Rosa Therapeutics, Inc. Insider Trading Update

Philip Nickson, Chief Business & Legal Officer at Monte Rosa Therapeutics, Inc., reported a sale of 5,845 shares of Common Stock on April 9, 2026. The sale was executed at a weighted average price of $17.6925 per share, with individual transactions ranging from $17.6901 to $17.71. Following these transactions, Mr. Nickson directly owns 55,000 shares of the company's stock. This filing is made on Form 4.