Form 4: Greenstreet Yvonne reports multiple insider transactions in ALNY

Rhea-AI Filing Summary

Greenstreet Yvonne reported multiple insider transaction types in a Form 4 filing for ALNY. The filing lists transactions totaling 21,167 shares at a weighted average price of $310.08 per share. Following the reported transactions, holdings were 85,662 shares.

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

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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).

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^*

Greenstreet Yvonne

(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
X	Officer (give title below)		Other (specify below)
	Chief Executive Officer

3. Date of Earliest Transaction (Month/Day/Year)
02/12/2026

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	02/12/2026		A(1)		14,209	A	$0.0	92,620	D
Common Stock	02/13/2026		S(2)		6,958	D	$310.0808(3)	85,662	D
Common Stock								407	I	by Managed Account(4)

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. On February 27, 2023, the reporting person was granted a performance-based stock unit (PSU) under the 2018 Stock Incentive Plan. The shares subject to the PSU vest based on the achievement of three specified performance measures. The shares reported were issued to the reporting person upon vesting of forty (40) percent of the shares subject to the PSU based on the issuer publicly reporting the achievement of non-GAAP operating income for fiscal year 2025 on February 12, 2026, as determined by the People, Culture and Compensation Committee of the Issuer Board of Directors.

2. Represents shares automatically sold by the Company on behalf of the reporting person pursuant to a mandatory sell-to-cover provision in the award agreement to cover minimum statutory tax withholding obligations.

3. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $302.55 to $314.60. The reporting person will provide to the issuer, any security holder of the issuer or the SEC staff, upon request, information regarding the number of shares sold at each price within the range.

4. Reflects shares of ALNY common stock acquired by the Reporting Person under the issuer 401(k) plan as a result of the issuer 401(k) matching contribution program.

	By: Brett Budzinski, Attorney-in-Fact For: Yvonne Greenstreet	02/17/2026
	** 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 stock transactions did ALNY CEO Yvonne Greenstreet report?

Yvonne Greenstreet reported a performance-based stock award and a related tax sale. She received 14,209 Alnylam common shares from a vested PSU, then 6,958 shares were automatically sold to cover required tax withholding obligations, leaving substantial direct and some indirect holdings in ALNY stock.

How many Alnylam (ALNY) shares were granted to the CEO in this Form 4?

The Form 4 shows a grant of 14,209 common shares at no cost. These shares came from vesting of a performance-based stock unit after Alnylam reported non-GAAP operating income for fiscal year 2025, as confirmed by the board’s People, Culture and Compensation Committee.

Why were 6,958 ALNY shares sold by Yvonne Greenstreet?

The 6,958 ALNY shares were sold under a mandatory sell-to-cover provision. The company automatically sold these shares on her behalf to meet minimum statutory tax withholding obligations arising from the equity award vesting, rather than as a discretionary open-market sale for personal liquidity.

What price did the ALNY CEO’s tax-related share sale achieve?

The reported weighted average sale price was $310.0808 per ALNY share. Footnotes state the shares were sold in multiple transactions, with prices ranging from $302.55 to $314.60, and detailed trade breakdowns are available from the company or the reporting person upon request.

How many Alnylam (ALNY) shares does the CEO own after these transactions?

After these transactions, Yvonne Greenstreet directly owned 85,662 ALNY common shares. She also indirectly held 407 additional shares through a managed account, giving her both direct and indirect exposure to Alnylam’s equity following the grant and tax-withholding sale activity.

What performance goal triggered the CEO’s PSU vesting at Alnylam (ALNY)?

The PSU vesting was triggered by achieving non-GAAP operating income for fiscal year 2025. On February 12, 2026, Alnylam publicly reported this performance, and the board’s People, Culture and Compensation Committee confirmed it, causing 40% of the PSU’s shares to vest and be issued.