X0609 4 2026-05-12 0 0001999480 Alto Neuroscience, Inc. ANRO 0001830326 Sanchez Ramiro false C/O ALTO NEUROSCIENCE, INC. 650 CASTRO STREET, SUITE 450 MOUNTAIN VIEW CA 94041 1 0 0 0 0 Stock Option (right to buy) 24.63 2026-05-12 4 A 0 10958 0 A 2036-05-11 Common Stock 10958 10958 D The shares underlying the option shall vest on the earlier of the one-year anniversary of the date of grant and the date of Issuer's next Annual Meeting following the date of grant, subject to the Reporting Person's continuous service through such vesting date. This option was issued to the Reporting Person pursuant to the Issuer's Non-Employee Director Compensation Policy, and was not sold to the Reporting Person. As such, the Reporting person did not pay any consideration for the derivative securities. /s/ Erin R. McQuade, Attorney-in-Fact 2026-05-14