X0609 4 2026-09-03 0001681087 Tectonic Therapeutic, Inc. TECX 0002023175 Schwabish Marc false C/O TECTONIC THERAPEUTIC, INC. 490 ARSENAL WAY, SUITE 200 WATERTOWN MA 02472 false true false false Chief Business Officer 0 Employee Stock Option (Right to Buy) 29.92 2026-09-03 4 A 0 17750 0 A 2036-09-02 Common Stock 17750 17750 D 1/8th of the shares subject to the option vest on September 3, 2026 with the remaining shares subject to the option vesting in the following 42 equal monthly installments beginning on October 3, 2026, subject to the Reporting Person's continued service to the Issuer on each such vesting date. /s/ Daniel Lochner, Attorney-in-Fact 2026-09-08