X0202 SCHEDULE 13G/A 0000919574-25-002493 0001569064 XXXXXXXX LIVE 1 Common stock, par value $0.0001 per share 06/30/2026 0001826457 Monte Rosa Therapeutics, Inc. 61225M102 321 Harrison Avenue Suite 900 Boston MA 02118 Rule 13d-1(c) Montanova Capital, LLC b DE 0.00 3549539.00 0.00 3549539.00 3549539.00 N 4.2 IA OO Averill Master Fund, Ltd. b E9 0.00 3215486.00 0.00 3215486.00 3215486.00 N 3.8 CO Aaron Cowen b X1 0.00 3549539.00 0.00 3549539.00 3549539.00 N 4.2 HC IN Monte Rosa Therapeutics, Inc. 321 Harrison Avenue, Suite 900, Boston, MA 02118 Montanova Capital, LLC Averill Master Fund, Ltd. Aaron Cowen Montanova Capital, LLC 11 E 26th Street, 16th Floor New York, New York 10010 United States of America Averill Master Fund, Ltd. c/o Maples Corporate Services Limited P.O. Box 309 Ugland House Grand Cayman KY1-1104 Cayman Islands Aaron Cowen c/o Montanova Capital, LLC 11 E 26th Street, 16th Floor New York, New York 10010 United States of America Montanova Capital, LLC - Delaware Averill Master Fund, Ltd. - Cayman Islands Aaron Cowen - United States Y Montanova Capital, LLC - 3,549,539 Averill Master Fund, Ltd. - 3,215,486 Aaron Cowen - 3,549,539 Suvretta Capital Management, LLC - 4.2% Averill Master Fund, Ltd. - 3.8% Aaron Cowen - 4.2% Montanova Capital, LLC - 0 Averill Master Fund, Ltd. - 0 Aaron Cowen - 0 Montanova Capital, LLC - 3,549,539 Averill Master Fund, Ltd. - 3,215,486 Aaron Cowen - 3,549,539 Montanova Capital, LLC - 0 Averill Master Fund, Ltd. - 0 Aaron Cowen - 0 Montanova Capital, LLC - 3,549,539 Averill Master Fund, Ltd. - 3,215,486 Aaron Cowen - 3,549,539 N Y Y N Please see Exhibit B attached hereto. Y Y N By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were not acquired and are not held for the purpose of or with the effect of changing or influencing the control of the issuer of the securities and were not acquired and are not held in connection with or as a participant in any transaction having that purpose or effect, other than activities solely in connection with a nomination under § 240.14a-11. Exhibit A - Joint Filing Agreement Exhibit B - Control Person Identification Montanova Capital, LLC /s/ Andrew Nathanson 08/14/2026 Averill Master Fund, Ltd. /s/ Andrew Nathanson 08/14/2026 Aaron Cowen /s/ Aaron Cowen 08/14/2026 * Each Reporting Person disclaims beneficial ownership of the reported securities except to the extent of his, her or its pecuniary interest therein, and this report shall not be deemed an admission that such Reporting Person is the beneficial owner of the securities for purposes of Section 16 of the Securities Exchange Act of 1934, as amended, or for any other purpose. To the extent that "ownership of 5 percent or less of a class" was indicated in Item 5, such response only applies to the Reporting Person(s) that indicated elsewhere herein that it beneficially owns five percent (5%) or less of the class.