[Form 4] Alnylam Pharmaceuticals, Inc. Insider Trading Activity

Rhea-AI Filing Summary

Michael W. Bonney, a director of Alnylam Pharmaceuticals (ALNY), reported transactions on 08/18/2025 under a Rule 10b5-1 trading plan. On that date he acquired 11,250 shares of ALNY common stock at a reported price of $70.20 and sold 11,250 shares at a reported price of $450.00, both transactions recorded under the same date. Following the reported transactions his direct beneficial ownership is listed as 16,804 shares, and he also has 4,000 shares held indirectly by the Michael W. Bonney Revocable Trust. The filing notes the 10b5-1 plan was adopted on November 12, 2024, and that the related stock option was fully vested as of June 3, 2017.

Positive

• Transactions executed under a documented Rule 10b5-1(c) trading plan adopted November 12, 2024, which supports procedural compliance
• Filing discloses vested status of related option (fully vested as of June 3, 2017), improving clarity on exercisability
• Indirect trust holdings disclosed (4,000 shares held by Michael W. Bonney Revocable Trust), increasing transparency of beneficial ownership

Negative

• Direct beneficial ownership decreased from 28,054 shares to 16,804 shares following reported transactions, reflecting a net reduction in reported direct holdings

Insights

Securities Analyst

TL;DR: Director executed offsetting buy and sell transactions under a 10b5-1 plan, leaving material direct and trust-held positions.

The filing shows same-day acquisition and disposition of 11,250 ALNY shares by director Michael W. Bonney under a Rule 10b5-1(c) plan adopted November 12, 2024. The report records an acquisition price of $70.20 and a disposal price of $450.00 for the same number of shares, and indicates the option that produced shares was vested on June 3, 2017. Post-transaction direct holdings are reported at 16,804 shares with an additional 4,000 shares held indirectly via a revocable trust. From a reporting and governance perspective, the use of a documented 10b5-1 plan provides procedural protection for the trades and clarifies timing, while the disclosure of both direct and trust-held positions gives transparency to total beneficial ownership.

Corporate Governance Expert

TL;DR: Trades appear planned and documented via 10b5-1; disclosure is complete regarding vested option status and trust holdings.

The Form 4 discloses that the transactions were executed pursuant to a 10b5-1 plan and that the underlying stock option was fully vested in 2017, which are important governance details. The filing also identifies indirect ownership through the Michael W. Bonney Revocable Trust and includes executed-signature confirmation by an attorney-in-fact. These elements support transparency and compliance with Section 16 reporting obligations, with no additional governance issues stated in the filing.

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^*

BONNEY MICHAEL W

(Last) (First) (Middle)

675 WEST KENDALL STREET

HENRI A. TERMEER SQUARE

(Street)

CAMBRIDGE MA 02142

(City) (State) (Zip)

2. Issuer Name and Ticker or Trading Symbol
ALNYLAM PHARMACEUTICALS, INC. [ ALNY ]

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

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

3. Date of Earliest Transaction (Month/Day/Year)
08/18/2025

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	08/18/2025		M(1)		11,250	A	$70.2	28,054	D
Common Stock	08/18/2025		S(1)		11,250	D	$450	16,804	D
Common Stock								4,000	I	by Trust(2)

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)	$70.2	08/18/2025		M(1)			11,250	06/03/2017(3)	06/03/2026	Common Stock	11,250	$0.0	0	D

Explanation of Responses:

1. This transaction was made pursuant to a Rule 10b5-1(c) trading plan adopted by the Reporting Person on November 12, 2024.

2. The shares of ALNY common stock were purchased by the Michael W. Bonney Revocable Trust, of which the reporting person is trustee.

3. The stock option was fully vested as of June 3, 2017.

	By: Brett Budzinski, Attorney-in-Fact For: Michael W. Bonney	08/19/2025
	** 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 transactions did ALNY director Michael W. Bonney report on Form 4?

He reported acquiring 11,250 shares and selling 11,250 shares of ALNY common stock on 08/18/2025.

Were the trades by Michael W. Bonney part of a 10b5-1 plan?

Yes. The filing states the transactions were made pursuant to a Rule 10b5-1(c) trading plan adopted on November 12, 2024.

What prices were reported for the acquisition and sale?

The acquisition is reported at $70.20 and the sale at $450.00 per share, both on 08/18/2025.

How many ALNY shares does Michael W. Bonney beneficially own after the transactions?

Directly: 16,804 shares. Additionally, 4,000 shares are held indirectly by the Michael W. Bonney Revocable Trust.

Was the underlying stock option exercisable at the time of the transaction?

Yes. The Form 4 notes the related stock option was fully vested as of June 3, 2017.