13D Filings
Tectonic Therapeutic, Inc.
TECX
Amendment
Ownership

6.30%

Total Shares

657,976

Issuer CIK

1681087

CUSIP

878972108

Event Date

Apr 2, 2025

Accepted

Apr 7, 2025, 05:19 PM

Reporting Persons (8)
Joint Filing

This is a joint filing. The reported shares may overlap between reporting persons and should not be summed.

NameType% of ClassAggregateSole VotingShared Voting
Terrance McGuire
Individual
6.30%657,9760657,976
Polaris Partners IX, L.P.
Partnership
3.10%573,0620573,062
Polaris Partners GP IX, L.L.C.
Other
3.10%573,0620573,062
Jonathan Flint
Individual
0.50%84,914084,914
Polaris Founders Capital Fund II, L.P.
Partnership
0.30%64,652064,652
Polaris Founders Capital Fund Management Co. II, L.L.C.
Other
0.30%64,652064,652
Polaris Founders Capital Fund Management Co. I, L.L.C.
Other
0.10%20,262020,262
Polaris Founders Capital Fund I, L.P.
Partnership
0.10%20,262020,262
Disclosure Items (2)

Security Title

Common Stock, $0.0001 par value per share

Issuer Name

Tectonic Therapeutic, Inc.

Issuer Address

490 Arsenal Way, Watertown, MA, 02472

Percentage of Class

See Items 7-11 and 13 of the cover pages of this Amendment for each Reporting Person and the corresponding comments.

Number of Shares

See Items 7-11 and 13 of the cover pages of this Amendment for each Reporting Person and the corresponding comments.

Transactions

On April 3, 2025, PP IX entered into Stock Purchase Agreements with each of Timothy A. Springer ("Dr. Springer") and TAS Partners LLC ("TAS"), pursuant to which Dr. Springer purchased 87,500 shares of Common Stock from PP IX at a purchase price of $17.10 per share, or $1,496,250 in the aggregate, and TAS purchased 412,500 shares of Common Stock at a purchase price of $17.10 per share, or $7,053,750 in the aggregate. The closing occurred on April 7, 2025.

Date of 5% Ownership

April 7, 2025