Tectonic Therapeutic (TECX) CSO has 1,748 shares withheld for tax

Rhea-AI Filing Summary

Tectonic Therapeutic, Inc. insider Peter McNamara, Chief Scientific Officer, reported a routine share withholding related to equity compensation. On February 4, 2026, the issuer withheld 1,748 shares of common stock at $23.22 per share to cover his tax obligations on vested restricted stock units, leaving him with 39,131 directly held shares.

SEC Form 4

FORM 4

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

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Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).

Check this box to indicate that a transaction was made pursuant to a contract, instruction or written plan for the purchase or sale of equity securities of the issuer that is intended to satisfy the affirmative defense conditions of Rule 10b5-1(c). See Instruction 10.

1. Name and Address of Reporting Person^*

McNamara Peter

(Last) (First) (Middle)

C/O TECTONIC THERAPEUTIC, INC.

490 ARSENAL WAY, SUITE 200

(Street)

WATERTOWN MA 02472

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Tectonic Therapeutic, Inc. [ TECX ]

5. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	Chief Scientific Officer

3. Date of Earliest Transaction (Month/Day/Year)
02/04/2026

4. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)		4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned Following Reported Transaction(s) (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
			Code	V	Amount	(A) or (D)	Price
Common Stock	02/04/2026		F		1,748(1)	D	$23.22	39,131	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)		5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
				Code	V	(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. This transaction reported represents the withholding of shares by the Issuer to satisfy the Reporting Person's tax withholding obligations in connection with the vesting and settlement of the restricted stock units granted on February 4, 2025.

	/s/ Daniel Lochner, Attorney-in-Fact	02/10/2026
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
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FAQ

What insider transaction did Tectonic Therapeutic (TECX) disclose for Peter McNamara?

Tectonic Therapeutic reported that Chief Scientific Officer Peter McNamara had 1,748 shares of common stock withheld on February 4, 2026. The issuer used these shares to satisfy his tax withholding obligations arising from the vesting and settlement of previously granted restricted stock units.

How many Tectonic Therapeutic (TECX) shares were involved in Peter McNamara’s February 2026 transaction?

The transaction covered 1,748 shares of Tectonic Therapeutic common stock at a reference price of $23.22 per share. These shares were not sold on the open market but withheld by the company to cover Peter McNamara’s tax obligations tied to vested restricted stock units.

Did Peter McNamara sell Tectonic Therapeutic (TECX) shares on the open market?

The filing describes a tax withholding event rather than an open market sale. Tectonic Therapeutic withheld 1,748 shares from Peter McNamara to satisfy his tax obligations when restricted stock units vested and settled, meaning the shares were retained by the issuer instead of being sold externally.

How many Tectonic Therapeutic (TECX) shares does Peter McNamara own after the reported transaction?

After the tax withholding event, Peter McNamara beneficially owns 39,131 shares of Tectonic Therapeutic common stock. The filing classifies this ownership as direct, reflecting his remaining stake following the share withholding related to the vesting of restricted stock units granted in February 2025.

What was the purpose of the share withholding reported by Tectonic Therapeutic (TECX)?

The share withholding satisfied tax obligations triggered when Peter McNamara’s restricted stock units vested and settled. Instead of paying taxes in cash, 1,748 shares of common stock were withheld by Tectonic Therapeutic, a common administrative mechanism tied to equity-based compensation awards for executives.