Yvonne Greenstreet - 02 Mar 2026 Form 4 Insider Report for ALNYLAM PHARMACEUTICALS, INC. (ALNY)

Signature
By: Brett Budzinski, Attorney-in-Fact For: Yvonne Greenstreet
Issuer symbol
ALNY
Transactions as of
02 Mar 2026
Net transactions value
-$2,227,698
Form type
4
Filing time
04 Mar 2026, 19:29:11 UTC
Previous filing
02 Mar 2026
Next filing
06 Mar 2026

Reporting Owners (1)

Name Relationship Address Signature Signature date CIK
Greenstreet Yvonne Chief Executive Officer, Director 675 WEST KENDALL STREET, HENRI A. TERMEER SQUARE, CAMBRIDGE By: Brett Budzinski, Attorney-in-Fact For: Yvonne Greenstreet 04 Mar 2026 0001446125

Transactions Table

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Ownership Footnotes
transaction ALNY Common Stock Award +13,844 +15% $0.000000* 105,427 02 Mar 2026 Direct F1
transaction ALNY Common Stock Sale $64,724 -200 -0.19% $323.62 105,227 02 Mar 2026 Direct F2, F3
transaction ALNY Common Stock Sale $124,016 -382 -0.36% $324.65 104,845 02 Mar 2026 Direct F2, F4
transaction ALNY Common Stock Sale $357,542 -1,098 -1% $325.63 103,747 02 Mar 2026 Direct F2, F5
transaction ALNY Common Stock Sale $545,446 -1,669 -1.6% $326.81 102,078 02 Mar 2026 Direct F2, F6
transaction ALNY Common Stock Sale $458,410 -1,399 -1.4% $327.67 100,679 02 Mar 2026 Direct F2, F7
transaction ALNY Common Stock Sale $139,373 -424 -0.42% $328.71 100,255 02 Mar 2026 Direct F2, F8
transaction ALNY Common Stock Sale $238,051 -722 -0.72% $329.71 99,533 02 Mar 2026 Direct F2, F9
transaction ALNY Common Stock Sale $114,474 -346 -0.35% $330.85 99,187 02 Mar 2026 Direct F2, F10
transaction ALNY Common Stock Sale $132,440 -399 -0.4% $331.93 98,788 02 Mar 2026 Direct F2, F11
transaction ALNY Common Stock Sale $53,222 -160 -0.16% $332.64 98,628 02 Mar 2026 Direct F2, F12
holding ALNY Common Stock 407 02 Mar 2026 by Managed Account F13

Derivative Securities (e.g., puts, calls, warrants, options, convertible securities)

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Underlying Class Amount Exercise Price Ownership Footnotes
transaction ALNY Stock Option (right to buy) Award +30,425 $0.000000* 30,425 02 Mar 2026 Common Stock 30,425 $325.07 Direct F14
transaction ALNY Stock Price Performance Stock Unit Award +110,746 $0.000000* 110,746 02 Mar 2026 Common Stock 110,746 $0.000000 Direct F15
* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id Content
F1 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 over a three-year period, with one third vesting on each of the first, second and third anniversaries of the grant date, subject to the Reporting Persons continuous service with the Issuer as of each such vesting date.
F2 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.
F3 The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $323.16 to $324.15. 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.
F4 The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $324.20 to $325.20. 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.
F5 The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $325.21 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.
F6 The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $326.23 to $327.23. 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.
F7 The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $327.24 to $328.24. 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.
F8 The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $328.28 to $329.26. 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.
F9 The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $329.29 to $330.29. 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.
F10 The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $330.30 to $331.30. 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.
F11 The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $331.32 to $332.31. 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.
F12 The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $332.34 to $332.24. 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.
F13 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.
F14 The stock option vests as to 25% of the shares on the first anniversary of the grant date and the remaining shares vest in equal installments at the end of each successive three-month period thereafter until the fourth anniversary of the grant date, subject to the Reporting Persons continuous service with the Issuer as of each such vesting date.
F15 Stock price performance unit award (PSU) granted pursuant to the Second Amended and Restated 2018 Stock Incentive Plan. The amount reported is the maximum number of PSUs that may be earned upon achievement of pre-set stock price thresholds. Subject to the terms and conditions of the PSU award agreement, the PSU vests on December 31, 2029 (Vesting Date) and between 50% and 200% of the target number of 55,373 PSUs may be earned if the highest average closing price that is achieved over a 30 consecutive trading period (Future Average Stock Price) in the six months preceding the vesting date (Measurement Period) meets or exceeds certain thresholds. If the Future Average Stock Price does not meet or exceed the baseline threshold price during the Measurement Period, no portion of the PSU will be earned, and all PSUs will be forfeited on the Vesting Date.