X0609 4 2026-04-01 0001681087 Tectonic Therapeutic, Inc. TECX 0001365343 Nader Francois false C/O TECTONIC THERAPEUTIC, INC. 490 ARSENAL WAY, SUITE 200 WATERTOWN MA 02472 true false false false 0 Stock Option (Right to Buy) 30.78 2026-04-01 4 A 0 20400 0 A 2036-03-31 Common Stock 20400 20400 D One Third (1/3) of the shares subject to the option shall vest on April 1, 2027, and the balance shall vest in 24 equal monthly installments thereafter, subject in each case, to the Reporting Person providing continuous service to the Issuer through each applicable vesting date. /s/ Daniel Lochner, Attorney-in-Fact 2026-04-03