RNA Form 4: CFO Michael MacLean Disposes of 30,914 Shares

Rhea-AI Filing Summary

Michael F. MacLean, Chief Financial Officer of Avidity Biosciences, Inc. (RNA), reported insider stock sales on a Form 4. On 08/06/2025 he disposed of 30,914 shares of Avidity common stock under a Rule 10b5-1 trading plan adopted 07/08/2024 at a weighted-average price of $42.7264 per share (individual sale prices ranged from $40.15 to $43.92). After the reported transactions he beneficially owned 65,806 shares. The Form 4 was signed by an attorney-in-fact on 08/15/2025. The filing states the reporting person will provide details on the number of shares sold at each price upon request.

Positive

• None.

Negative

• Insider sale by the CFO: Disposal of 30,914 shares could be viewed as a reduction in insider ownership concentration, which some investors may interpret negatively.
• Partial disclosure of per-price quantities: The filing reports a weighted-average price and a price range but does not list the number of shares sold at each individual price without a request.

Insights

Securities Analyst

TL;DR: CFO sold a material but not controlling stake under a pre-established 10b5-1 plan.

The sale of 30,914 shares at a weighted-average price of $42.7264 is precisely documented and executed pursuant to a Rule 10b5-1 plan adopted 07/08/2024, which mitigates concerns about opportunistic insider trading because trades were pre-planned. The remaining beneficial ownership of 65,806 shares is disclosed, allowing investors to track continuing insider exposure. This disclosure is routine for senior officers and does not by itself change financial fundamentals.

Compliance/Risk Analyst

TL;DR: Filing is compliant and includes required 10b5-1 disclosure and price range detail.

The Form 4 includes the Rule 10b5-1 plan checkbox and explains the weighted-average price plus the range of executed trade prices ($40.15 to $43.92). The reporting person offers to provide per-price sale counts on request, which supports transparency. The document is signed by an attorney-in-fact and follows Form 4 requirements; there are no apparent reporting deficiencies in the text provided.

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
Estimated average burden
hours per response:			0.5

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^*

MacLean Michael F

(Last) (First) (Middle)

C/O AVIDITY BIOSCIENCES, INC.

10578 SCIENCE CENTER DRIVE, SUITE 125

(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 Financial Officer

3. Date of Earliest Transaction (Month/Day/Year)
08/06/2025

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	08/06/2025		S(1)		30,914	D	$42.7264(2)	65,806	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. The sales reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan previously adopted by the Reporting Person on July 8, 2024.

2. This represents a weighted-average price. These shares were sold in multiple transactions at prices ranging from $40.15 to $43.92. The Reporting Person undertakes to provide the Issuer, any securityholder of the Issuer, or the Staff of the Securities and Exchange Commission, upon request, full information regarding the number of shares sold at each separate price within the range set forth in this footnote.

Remarks:

	/s/ John B. Moriarty, Jr., J.D., Attorney-in-Fact	08/15/2025
	** 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 Avidity Biosciences (RNA) reporting person Michael F. MacLean do on 08/06/2025?

He sold 30,914 shares of Avidity common stock under a Rule 10b5-1 plan on 08/06/2025.

At what price were the shares sold according to the Form 4 for RNA?

The filing reports a weighted-average price of $42.7264 with individual sale prices ranging from $40.15 to $43.92.

How many Avidity shares does Michael F. MacLean beneficially own after the transaction?

After the reported sales he beneficially owned 65,806 shares.

Was the sale part of a pre-established trading plan?

Yes. The Form 4 states the sales were effected pursuant to a Rule 10b5-1 trading plan adopted July 8, 2024.

When was the Form 4 signed and by whom?

The Form 4 signature block shows it was signed by an attorney-in-fact on 08/15/2025.