Tax-withholding stock sale for Alnylam (ALNY) EVP disclosed

Rhea-AI Filing Summary

ALNYLAM PHARMACEUTICALS, INC. executive officer Tanguler Tolga reported automatic sales of common stock tied to equity compensation. On March 4, 2026, a total of 2,309 shares of common stock were sold in multiple open‑market transactions.

According to a footnote, these shares were sold by the company on the reporting person’s behalf under a mandatory sell-to-cover provision to satisfy minimum statutory tax withholding upon vesting of restricted stock units. After these sales, the reporting person directly held 34,297 common 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^*

Tanguler Tolga

(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)

	Director		10% Owner
X	Officer (give title below)		Other (specify below)
	EVP, Chief Commercial Officer

3. Date of Earliest Transaction (Month/Day/Year)
03/04/2026

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	03/04/2026		S(1)		106	D	$319.03(2)	36,500	D
Common Stock	03/04/2026		S(1)		102	D	$320.01(3)	36,398	D
Common Stock	03/04/2026		S(1)		215	D	$320.81(4)	36,183	D
Common Stock	03/04/2026		S(1)		289	D	$321.82(5)	35,894	D
Common Stock	03/04/2026		S(1)		350	D	$323.01(6)	35,544	D
Common Stock	03/04/2026		S(1)		767	D	$323.84(7)	34,777	D
Common Stock	03/04/2026		S(1)		272	D	$324.88(8)	34,505	D
Common Stock	03/04/2026		S(1)		208	D	$325.67(9)	34,297	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 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 upon the vesting of restricted stock units.

2. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $318.27 to $319.27. 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.

3. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $319.28 to $320.28. 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. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $320.33 to $321.33. 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.

5. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $321.34 to $322.31. 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.

6. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $322.36 to $323.36. 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.

7. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $323.38 to $324.35. 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.

8. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $324.39 to $325.38. 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.

9. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $325.40 to $326.21. 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.

	By: Brett Budzinski, Attorney-in-Fact For: Tolga Tanguler	03/06/2026
	** 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).
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FAQ

What insider transaction did ALNY (Alnylam Pharmaceuticals) disclose?

Alnylam reported that executive officer Tanguler Tolga had 2,309 common shares sold on March 4, 2026. The sales were open‑market transactions executed by the company to cover tax withholding on vested restricted stock units.

Why were shares sold for ALNY executive Tanguler Tolga?

The shares were sold under a mandatory sell-to-cover provision in the equity award agreement. This provision required the company to sell shares to meet minimum statutory tax withholding obligations when restricted stock units vested.

How many ALNY shares were sold and at what price range?

In total, 2,309 common shares were sold in several trades. Footnotes state weighted average sale prices with ranges generally between about $318 and $326 per share, reflecting multiple transactions within each reported price range.

How many Alnylam (ALNY) shares does the executive hold after the sale?

Following the tax-related sales, the reporting person directly owned 34,297 shares of Alnylam common stock. This figure reflects the balance reported in the Form 4 after all eight open‑market sale transactions on March 4, 2026.

Were the ALNY insider stock sales discretionary or tax-related?

The filing describes the transactions as tax-related. A footnote explains the company automatically sold shares on the executive’s behalf under a mandatory sell-to-cover provision to satisfy required tax withholding tied to restricted stock unit vesting.

What role does the insider in this ALNY Form 4 hold?

The reporting person serves as EVP, Chief Commercial Officer of Alnylam Pharmaceuticals. The Form 4 reflects that this officer’s directly held common stock position changed due to tax-withholding sales connected to equity award vesting.