Alnylam (ALNY) director granted RSUs and stock options in new equity awards

Rhea-AI Filing Summary

ALNYLAM PHARMACEUTICALS, INC. director Stuart A. Arbuckle received equity awards on May 20, 2026. He was granted 671 restricted stock units, each representing one share of common stock, and a stock option for 1,441 shares at an exercise price of $298.48 per share. Both the RSUs and the option vest in full on the earlier of the first anniversary of the grant date or an earlier retirement or resignation that occurs no more than 90 days before that anniversary. Following these awards, Arbuckle holds 671 common shares and a vested-over-time option covering 1,441 underlying shares.

Insider Trade Summary

2 transactions reported

Mixed 2 txns

Insider Arbuckle Stuart A

Role null

Type	Security	Shares	Price	Value
Grant/Award	Stock Option (Right to Buy)	1,441	$0.00	--
Grant/Award	Common Stock	671	$0.00	--

Holdings After Transaction: Stock Option (Right to Buy) — 1,441 shares (Direct, null); Common Stock — 671 shares (Direct, null)

Footnotes (1)

1. These shares are represented by restricted stock units (RSUs) granted under the Second Amended and Restated 2018 Stock Incentive Plan. Each RSU represents a contingent right to receive one share of common stock. The RSUs will vest in full upon the earlier of the first anniversary of the grant date and the date of any earlier retirement or resignation of the Reporting Person, provided such date of retirement or resignation occurs no more than 90 days prior to the first anniversary of the grant date. The stock option will vest in full upon the earlier of the first anniversary of the grant date and the date of any earlier retirement or resignation of the Reporting Person, provided such date of retirement or resignation occurs no more than 90 days prior to the first anniversary of the grant date.

Key Figures

RSU grant size: 671 RSUs Option grant size: 1,441 shares Option exercise price: $298.48/share +3 more

6 metrics

RSU grant size 671 RSUs Restricted stock units granted May 20, 2026

Option grant size 1,441 shares Underlying common stock for new option grant

Option exercise price $298.48/share Conversion or exercise price for stock option

Option expiration May 20, 2036 Expiration date of stock option grant

Shares held after grant 671 shares Total common shares following RSU award

RSU vesting trigger 1-year anniversary or qualifying exit Earlier of first anniversary or retirement/resignation within 90 days

Key Terms

restricted stock units (RSUs), Second Amended and Restated 2018 Stock Incentive Plan, Stock Option (Right to Buy), vest in full, +1 more

5 terms

restricted stock units (RSUs) financial

"These shares are represented by restricted stock units (RSUs) granted under the Second Amended and Restated 2018 Stock Incentive Plan."

Restricted stock units (RSUs) are a type of company promise to give employees shares of stock in the future, usually after certain conditions like working for a set time. They are like a gift promised today that you receive later, which can become valuable if the company's stock price goes up. RSUs matter because they are a way companies reward employees and can be a significant part of compensation.

Second Amended and Restated 2018 Stock Incentive Plan financial

"These shares are represented by restricted stock units (RSUs) granted under the Second Amended and Restated 2018 Stock Incentive Plan."

Stock Option (Right to Buy) financial

"The stock option will vest in full upon the earlier of the first anniversary of the grant date..."

vest in full financial

"The RSUs will vest in full upon the earlier of the first anniversary of the grant date..."

contingent right financial

"Each RSU represents a contingent right to receive one share of common stock."

Form 4 Insider Transactions: What Each Field Means →

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).

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^*

Arbuckle Stuart A

(Last) (First) (Middle)

675 WEST KENDALL STREET

(Street)

CAMBRIDGE MASSACHUSETTS 02142

(City) (State) (Zip)

UNITED STATES

(Country)

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)

2a. Foreign Trading Symbol

3. Date of Earliest Transaction (Month/Day/Year)
05/20/2026

6. Individual or Joint/Group Filing (Check Applicable Line)

X	Form filed by One Reporting Person
	Form filed by More than One Reporting Person

4. If Amendment, Date of Original Filed (Month/Day/Year)

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	05/20/2026		A		671(1)	A	$0	671	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)	$298.48	05/20/2026		A		1,441		05/20/2027(2)	05/20/2036	Common Stock	1,441	$0	1,441	D

Explanation of Responses:

1. These shares are represented by restricted stock units (RSUs) granted under the Second Amended and Restated 2018 Stock Incentive Plan. Each RSU represents a contingent right to receive one share of common stock. The RSUs will vest in full upon the earlier of the first anniversary of the grant date and the date of any earlier retirement or resignation of the Reporting Person, provided such date of retirement or resignation occurs no more than 90 days prior to the first anniversary of the grant date.

2. The stock option will vest in full upon the earlier of the first anniversary of the grant date and the date of any earlier retirement or resignation of the Reporting Person, provided such date of retirement or resignation occurs no more than 90 days prior to the first anniversary of the grant date.

	Brett Budzinski, Attorney-in-Fact For: Stuart A. Arbuckle	05/22/2026
	** 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.
* Form 4: SEC 1474 (03-26)

FAQ

What equity awards did ALNY director Stuart A. Arbuckle receive on this Form 4?

Stuart A. Arbuckle received 671 restricted stock units and a stock option for 1,441 shares of Alnylam common stock. Both awards were granted on May 20, 2026 as part of his director compensation package.

How do the new RSUs for ALNY director Stuart A. Arbuckle vest?

The 671 RSUs vest in full on the earlier of the first anniversary of the May 20, 2026 grant date or Arbuckle’s retirement or resignation, provided that occurs no more than 90 days before that first anniversary, according to the award terms.

What are the key terms of Stuart A. Arbuckle’s ALNY stock option grant?

Arbuckle’s stock option covers 1,441 shares of Alnylam common stock at an exercise price of $298.48 per share. It vests in full on the earlier of the first anniversary of the grant date or qualifying retirement/resignation and expires on May 20, 2036.

Under which plan were Stuart A. Arbuckle’s ALNY equity awards granted?

The restricted stock units granted to Arbuckle are issued under Alnylam’s Second Amended and Restated 2018 Stock Incentive Plan. Each RSU represents a contingent right to receive one share of common stock once the vesting conditions are satisfied as described in the award terms.

What are Stuart A. Arbuckle’s holdings after the reported ALNY transactions?

After these awards, Arbuckle directly holds 671 shares of Alnylam common stock from the RSUs and a stock option covering 1,441 underlying shares. These positions reflect his equity-based compensation and potential future ownership if the option is exercised.