SCHEDULE 13D/A

Tectonic Therapeutic Inc

Common Stock, $0.0001 par value per share. · CUSIP: 878972108

Event date: 2025-02-05

Reporting persons may disclose overlapping interests. Their amounts are shown individually and are not added into a filing total.

Filing-level shares

Unavailable

Percent of class

Unavailable

• Terrance McGuireReported CIK 0001117003

  Shares: 1,157,977 · Class: 6.3%

• Polaris Partners IX, L.P.Reported CIK 0001779755

  Shares: 1,073,063 · Class: 5.8%

• Polaris Partners GP IX, L.L.C.Reported CIK 0001877150

  Shares: 1,073,063 · Class: 5.8%

• Polaris Founders Capital Fund I, L.P.

  Shares: 20,262 · Class: 0.1%

• Polaris Founders Capital Fund Management Co. I, L.L.C.

  Shares: 20,262 · Class: 0.1%

• Polaris Founders Capital Fund II, L.P.

  Shares: 64,652 · Class: 0.4%

• Polaris Founders Capital Fund Management Co. II, L.L.C.

  Shares: 64,652 · Class: 0.4%

• Jonathan FlintReported CIK 0001295676

  Shares: 84,914 · Class: 0.5%

Amounts are as disclosed in this filing. Schedule type alone does not establish investment intent.