Jeffrey V. Poulton - Oct 1, 2025 Form 4 Insider Report for ALNYLAM PHARMACEUTICALS, INC. (ALNY)

Signature
By: Brett Budzinski, Attorney-in-Fact For: Jeffrey V. Poulton
Stock symbol
ALNY
Transactions as of
Oct 1, 2025
Transactions value $
-$1,727,284
Form type
4
Date filed
10/3/2025, 05:14 PM
Previous filing
Aug 19, 2025

Reporting Owners (1)

Name Relationship Address Signature Signature date CIK
Poulton Jeffrey V. EVP, Chief Financial Officer 675 WEST KENDALL STREET, HENRI A. TERMEER SQUARE, CAMBRIDGE By: Brett Budzinski, Attorney-in-Fact For: Jeffrey V. Poulton 2025-10-03 0001782962

Transactions Table

Type Sym Class Transaction Value $ Shares Change % * Price $ Shares After Date Ownership Footnotes
transaction ALNY Common Stock Award $0 +3.11K +6.2% $0.00 53.2K Oct 1, 2025 Direct F1
transaction ALNY Common Stock Award $0 +4.64K +8.72% $0.00 57.9K Oct 1, 2025 Direct F2
transaction ALNY Common Stock Sale -$67K -150 -0.26% $446.53 57.7K Oct 2, 2025 Direct F3, F4
transaction ALNY Common Stock Sale -$32.7K -73 -0.13% $447.92 57.7K Oct 2, 2025 Direct F3, F5
transaction ALNY Common Stock Sale -$105K -234 -0.41% $448.77 57.4K Oct 2, 2025 Direct F3, F6
transaction ALNY Common Stock Sale -$146K -324 -0.56% $449.79 57.1K Oct 2, 2025 Direct F3, F7
transaction ALNY Common Stock Sale -$317K -704 -1.23% $450.81 56.4K Oct 2, 2025 Direct F3, F8
transaction ALNY Common Stock Sale -$195K -432 -0.77% $451.86 56K Oct 2, 2025 Direct F3, F9
transaction ALNY Common Stock Sale -$393K -869 -1.55% $452.69 55.1K Oct 2, 2025 Direct F3, F10
transaction ALNY Common Stock Sale -$194K -428 -0.78% $453.77 54.7K Oct 2, 2025 Direct F3, F11
transaction ALNY Common Stock Sale -$144K -317 -0.58% $454.84 54.3K Oct 2, 2025 Direct F3, F12
transaction ALNY Common Stock Sale -$43.3K -95 -0.17% $455.82 54.2K Oct 2, 2025 Direct F3, F13
transaction ALNY Common Stock Sale -$87.4K -191 -0.35% $457.43 54.1K Oct 2, 2025 Direct F3
transaction ALNY Common Stock Sale -$1.83K -4 -0.01% $457.64 54.1K Oct 2, 2025 Direct F3
holding ALNY Common Stock 57 Oct 1, 2025 by Managed Account F14
* An asterisk sign (*) next to the price indicates that the price is likely invalid.

Explanation of Responses:

Id Content
F1 On February 24, 2021, 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 four specified performance measures. The shares reported were issued to the reporting person upon vesting of one-quarter of the shares subject to the PSU based on the issuer publicly reporting the initiation of a Phase 3 clinical study of an RNAi therapeutic in development to treat a prevalent disease, as determined by the People, Culture and Compensation (PC&C) Committee of the Issuer Board of Directors on October 1, 2025.
F2 On March 1, 2024, the reporting person was granted a 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 thirty (30) percent of the shares subject to the PSU based on the issuer publicly reporting the initiation of a Phase 3 clinical study in a prevalent indication, as determined by the PC&C Committee on October 1, 2025.
F3 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 required to cover minimum statutory tax withholding obligations that became due upon the vesting and settlement of tranches of PSUs granted to the reporting person on February 24, 2021 and March 1, 2024.
F4 The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $446.19 to $447.19. 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 $447.21 to $448.21. 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 $448.25 to $449.24. 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.
F7 The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $449.26 to $450.26. 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.
F8 The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $450.29 to $451.29. 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.
F9 The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $451.31 to $452.31. 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.
F10 The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $452.33 to $453.31. 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.
F11 The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $453.37 to $454.37. 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 $454.38 to $455.34. 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 The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $455.42 to $456.09. 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.
F14 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.