[Form 4] Avidity Biosciences, Inc. Insider Trading Activity

Rhea-AI Filing Summary

Kathleen P. Gallagher, Chief Program Officer at Avidity Biosciences, Inc. (RNA), reported a sell-to-cover transaction tied to RSU vesting. On September 2, 2025 she sold 188 shares of Avidity common stock at $47.42 per share to satisfy tax withholding from RSUs that vested on August 30, 2025. The filing states the sale was executed under the issuer's sell-to-cover election and pursuant to an instruction letter intended to meet the affirmative defense conditions of Rule 10b5-1. After the transaction she beneficially owned 50,204 shares (direct).

Positive

• Transaction disclosed promptly on Form 4, showing compliance with Section 16 reporting requirements
• Sale executed under a sell-to-cover procedure and 10b5-1 instruction letter, indicating a non-discretionary, compliance-driven trade

Negative

• Insider sold 188 shares, modestly reducing beneficial ownership to 50,204 shares

Insights

Financial Analyst

TL;DR: Small, routine insider sell-to-cover after RSU vesting; no new discretionary trading signaled.

The Form 4 documents a modest automatic sale of 188 shares at $47.42 to satisfy tax withholding on vested RSUs. This is a common non-discretionary administrative transaction that reduces the insider's share count slightly to 50,204 shares. There are no derivative transactions or additional disposals disclosed. From a market-impact perspective, the trade size is immaterial relative to typical public float and contains no directional signal about management sentiment.

Corporate Governance Expert

TL;DR: Disclosure aligns with governance best practices; use of a 10b5-1 instruction letter is noted.

The filer indicates the sale was executed under an instruction letter intended to satisfy the affirmative defense of Rule 10b5-1, and the issuer's plan required sell-to-cover for tax withholding. That explicit disclosure supports transparency and compliance. No amendments or additional related-party arrangements are reported. This is a routine compliance action, not an opportunistic voluntary sale disclosed as part of an ad-hoc trading plan.

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

OMB APPROVAL

OMB Number:			3235-0287
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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).

X

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^*

Gallagher Kathleen P.

(Last) (First) (Middle)

C/O AVIDITY BIOSCIENCES, INC.

3020 CALLAN RD.

(Street)

SAN DIEGO CA 92121

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
Avidity Biosciences, Inc. [ RNA ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
09/02/2025

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	09/02/2025		S(1)		188	D	$47.42	50,204	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. Represents the number of shares required to be sold by the Reporting Person to cover tax withholding obligations in connection with the vesting of RSUs on August 30, 2025 and the sale of the resulting shares of common stock on September 2, 2025. This sale is mandated by the Issuer's election under its equity incentive plans to require the satisfaction of tax withholding obligations to be funded by a "sell-to-cover" transaction and does not represent a discretionary trade by the Reporting Person. The Reporting Person has executed an instruction letter for the automatic sale of such "sell-to-cover" shares, intended to satisfy the affirmative defense conditions of Rule 10b5-1.

Remarks:

	/s/ John B. Moriarty, Jr., J.D., Attorney-in-Fact	09/02/2025
	** 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).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.

FAQ

What did Kathleen P. Gallagher report on the Form 4 for Avidity Biosciences (RNA)?

The filing reports a sell-to-cover sale of 188 shares at $47.42 on September 2, 2025 to satisfy tax withholding from RSUs that vested on August 30, 2025.

Was the sale a discretionary trade or part of a plan?

The sale was executed under the issuer's sell-to-cover election and an instruction letter intended to meet the affirmative defense conditions of Rule 10b5-1, indicating it was non-discretionary.

How many shares does the reporting person own after the transaction?

Following the sale the reporting person beneficially owned 50,204 shares (reported as direct ownership).

Does the Form 4 show any options, warrants, or other derivative transactions?

No. Table II for derivative securities contains no entries; only a non-derivative common stock sale is reported.

When did the RSUs vest that triggered the sell-to-cover?

The RSUs vested on August 30, 2025, per the filing explanation; the resulting shares were sold on September 2, 2025.