X0508 4 2026-01-05 0001826457 Monte Rosa Therapeutics, Inc. GLUE 0001989401 Dunn Edmund MONTE ROSA THERAPEUTICS, INC. 321 HARRISON AVENUE, SUITE 900 BOSTON MA 02118 false true false false Principal Accounting Officer false Common Stock 2026-01-05 4 S false 1039 15.17 D 22693 D Represents shares required to be sold by the Reporting Person to cover tax withholding obligations in connection with the vesting of restricted stock units. These sales were automatic and not in the discretion of the Reporting Person. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $15.17 to $15.43, inclusive. The Reporting Person undertakes to provide to the Issuer, any security holder of the Issuer, or the staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range. /s/ Markus Warmuth, Attorney-in-Fact 2026-01-05