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

Rhea-AI Filing Summary

Avidity Biosciences insider activity: Teresa McCarthy, Chief Human Resources Officer, effected option exercise and share sales under a Rule 10b5-1 plan on 08/15/2025. She exercised a stock option with a $22.34 exercise price for 10,000 shares and immediately sold 10,000 common shares in multiple transactions at a weighted-average price of $46.5632, with trade prices ranging $45.36 to $47.50. After these transactions the reporting person beneficially owned 97,130 shares of common stock and held options covering 100,000 shares. The option shares were fully vested as of the exercise date.

Positive

• Trades executed under a Rule 10b5-1 plan, indicating pre-planned transactions rather than ad hoc insider sales.
• Option shares were fully vested at exercise date, confirming no acceleration or special vesting treatment.

Negative

• Insider sold 10,000 shares, reducing reported beneficial ownership from 107,130 to 97,130 shares.
• Sale price range disclosed indicates insider realized proceeds at significantly higher prices than the exercise price, representing a monetization event.

Insights

Financial Analyst

TL;DR: Insider exercised vested options and sold 10,000 shares under a pre-established 10b5-1 plan; net holdings remain material.

The transaction shows an insider monetizing equity created by a lower-priced option exercise at $22.34 and selling at a weighted-average of $46.5632, realizing the spread between exercise price and sale proceeds. The sales were executed under a Rule 10b5-1 plan adopted April 11, 2025, which indicates trades were pre-planned rather than opportunistic. Post-transaction beneficial ownership of 97,130 shares plus options on 100,000 shares leaves the officer with continued meaningful exposure to company equity.

Corporate Governance Expert

TL;DR: Transaction complies with insider-plan disclosure norms; 10b5-1 adoption and full vesting are explicitly disclosed.

The filing discloses material compliance details: the trades were made pursuant to a 10b5-1 trading plan adopted April 11, 2025, and the shares subject to the option were fully vested as of the exercise date. The reporting includes weighted-average sale price range and a willingness to provide detailed execution prices on request, which aligns with robust disclosure practices for Form 4 filings.

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^*

McCarthy Teresa

(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 Human Resources Officer

3. Date of Earliest Transaction (Month/Day/Year)
08/15/2025

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	08/15/2025		M(1)		10,000	A	$22.34	107,130	D
Common Stock	08/15/2025		S(1)		10,000	D	$46.5632(2)	97,130	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
Stock Option (Right to Buy)	$22.34	08/15/2025		M(1)			10,000	(3)	02/01/2031	Common Stock	10,000	$0	100,000	D

Explanation of Responses:

1. The exercise and sales reported on this Form 4 were effected pursuant to a Rule 10b5-1 trading plan previously adopted by the Reporting Person on April 11, 2025.

2. This represents a weighted-average price. These shares were sold in multiple transactions at prices ranging from $45.36 to $47.50. 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.

3. The shares subject to this option award are fully vested and exercisable as of the date hereof.

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 Teresa McCarthy (RNA) do on 08/15/2025?

She exercised a stock option for 10,000 shares at an exercise price of $22.34 and sold 10,000 common shares at a weighted-average price of $46.5632.

Were these trades part of a pre-arranged plan?

Yes. The Form 4 states the transactions were effected pursuant to a Rule 10b5-1 trading plan adopted April 11, 2025.

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

After the reported transactions the reporting person beneficially owned 97,130 shares of common stock.

How many options does the reporting person hold following the filing?

The filing reports beneficial ownership of derivative securities representing 100,000 shares (stock options) following the transactions.

What was the sale price range for the shares sold?

Shares were sold in multiple transactions at prices ranging from $45.36 to $47.50, with a reported weighted-average of $46.5632.