Avidity Biosciences (RNA) CEO sells shares to cover RSU taxes via 10b5-1 plan

Rhea-AI Filing Summary

Avidity Biosciences, Inc. reported an insider transaction by President, CEO, and director Sarah Boyce. On January 7, 2026, she sold 8,576 shares of common stock at $72.23 per share. After this transaction, she beneficially owned 283,394 shares directly.

According to the disclosure, the sale was made solely to cover tax withholding obligations arising from the vesting of restricted stock units (RSUs) on January 6, 2026. The issuer’s equity incentive plans require these taxes to be funded through a mandatory “sell-to-cover” transaction, so this did not represent a discretionary trade. The filing notes that Boyce executed an instruction letter for the automatic sale of these shares, intended to satisfy the affirmative defense conditions of Rule 10b5-1.

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^*

Boyce Sarah

(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)

X	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	President and CEO

3. Date of Earliest Transaction (Month/Day/Year)
01/07/2026

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	01/07/2026		S		8,576(1)	D	$72.23	283,394	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 January 6, 2026 and the sale of the resulting shares of common stock on January 7, 2026. 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	01/09/2026
	** 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).
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 insider transaction did Avidity Biosciences (RNA) report in this Form 4?

The filing reports that Sarah Boyce, President, CEO, and director of Avidity Biosciences, Inc., sold 8,576 shares of the company’s common stock on January 7, 2026.

How many Avidity Biosciences (RNA) shares did CEO Sarah Boyce sell and at what price?

CEO Sarah Boyce sold 8,576 shares of Avidity Biosciences common stock at a price of $72.23 per share.

How many Avidity Biosciences (RNA) shares does Sarah Boyce own after this transaction?

Following the reported sale, Sarah Boyce beneficially owned 283,394 shares of Avidity Biosciences common stock in direct ownership.

Why were Sarah Boyce’s Avidity Biosciences (RNA) shares sold in this Form 4 filing?

The filing explains that the 8,576 shares were sold to cover tax withholding obligations related to the vesting of RSUs on January 6, 2026, using a mandated “sell-to-cover” transaction under the issuer’s equity incentive plans.

Was Sarah Boyce’s sale of Avidity Biosciences (RNA) shares a discretionary trade?

No. The disclosure states that the sale is mandated by the issuer’s election under its equity incentive plans for a “sell-to-cover” transaction and does not represent a discretionary trade by Sarah Boyce.

How does Rule 10b5-1 relate to this Avidity Biosciences (RNA) insider sale?

The filing notes that Sarah Boyce executed an instruction letter for the automatic sale of the “sell-to-cover” shares, which is intended to satisfy the affirmative defense conditions of Rule 10b5-1 for pre-arranged trading plans.