[Form 4] Tectonic Therapeutic, Inc. Insider Trading Activity

Rhea-AI Filing Summary

Marcella K. Ruddy, Chief Medical Officer of Tectonic Therapeutic, Inc. (TECX), received equity awards on 09/25/2025. The filing shows a grant of 5,370 restricted stock units (each convertible to one share) that vest in three equal annual installments on 09/25/2026, 09/25/2027 and 09/25/2028, subject to continued service. An employee stock option with a $14.71 exercise price covering 9,750 shares was also granted on 09/25/2025; those options vest in 48 equal monthly installments beginning 10/25/2025 and expire 09/24/2035. After these transactions, Ms. Ruddy beneficially owns 55,311 shares. The Form 4 is signed by an attorney-in-fact on 09/29/2025.

Insights

Corporate Governance Expert

TL;DR: Routine executive equity grants align officer incentives to company performance without unusual terms.

The grants reported are standard for senior executives: time‑based restricted stock units and an option with a typical ten‑year term and multi‑year vesting. The RSU vesting in three annual installments provides long‑term retention, while the 48‑month monthly vesting for the option phases in more gradually. No accelerated vesting, cashless exercise terms, or related‑party transactions are disclosed in this filing. The reported post‑transaction beneficial ownership of 55,311 shares quantifies the officer's stake but the filing does not state total outstanding shares, so relative ownership percentage cannot be derived from this document alone.

Compensation Analyst

TL;DR: Award mix and schedules reflect standard retention and incentive design for a C‑suite medical officer.

The combination of restricted stock units and options balances immediate equity value potential with longer‑term upside tied to stock price appreciation. The option strike of $14.71 and ten‑year term are typical; monthly vesting for the option after a one‑month cliff supports gradual retention. The RSUs carry no purchase price and vest in equal annual tranches, emphasizing retention over immediate liquidity. The filing lacks information on grant date valuation or target award sizing relative to market peers or total company dilution, limiting deeper pay‑for‑performance assessment.

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).

1. Name and Address of Reporting Person^*

Ruddy Marcella K.

(Last) (First) (Middle)

C/O TECTONIC THERAPEUTIC, INC.

490 ARSENAL WAY, SUITE 210

(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 Medical Officer

3. Date of Earliest Transaction (Month/Day/Year)
09/25/2025

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	09/25/2025		A		5,370(1)	A	$0	55,311	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
Employee Stock Option (Right to Buy)	$14.71	09/25/2025		A		9,750		(2)	09/24/2035	Common Stock	9,750	$0	9,750	D

Explanation of Responses:

1. These shares are represented by restricted stock units. Each restricted stock unit represents a contingent right to receive one share of common stock of the Issuer. The shares shall vest in 3 equal annual installments on each of September 25, 2026, September 25, 2027 and September 25, 2028, subject to the Reporting Person's continued service to the Issuer on each such vesting date.

2. The shares subject to the option vest in 48 equal monthly installments beginning on October 25, 2025, subject to the Reporting Person's continued service to the Issuer on each such vesting date.

	/s/ Daniel Lochner, Attorney-in-Fact	09/29/2025
	** 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).
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