Form 4 • Statement of Changes in Beneficial Ownership
Type
Sell
Net shares
+1,277
% of shares
5.60%
Amount (USD)
$1,130,131
Insider confidence score
95.0 out of 100
Positive
Security
Common Stock
Action
Grant
Date
2026-03-02
Code
A
Net shares
+4,769.0
Acquired/Disposed
Acquired
Shares Owned Before
22,129.0
Shares Owned After
26,898.0
Security
Common Stock
Action
Sell
Date
2026-03-02
Code
S
Net shares
-50.0
Price per Share
$323.62
Amount (USD)
$16,181.00
Acquired/Disposed
Disposed
Shares Owned Before
26,898.0
Shares Owned After
26,848.0
Security
Common Stock
Action
Sell
Date
2026-03-02
Code
S
Net shares
-97.0
Price per Share
$324.65
Amount (USD)
$31,491.05
Acquired/Disposed
Disposed
Shares Owned Before
26,848.0
Shares Owned After
26,751.0
Security
Common Stock
Action
Sell
Date
2026-03-02
Code
S
Net shares
-277.0
Price per Share
$325.63
Amount (USD)
$90,199.51
Acquired/Disposed
Disposed
Shares Owned Before
26,751.0
Shares Owned After
26,474.0
Security
Common Stock
Action
Sell
Date
2026-03-02
Code
S
Net shares
-421.0
Price per Share
$326.81
Amount (USD)
$137,587.01
Acquired/Disposed
Disposed
Shares Owned Before
26,474.0
Shares Owned After
26,053.0
Security
Common Stock
Action
Sell
Date
2026-03-02
Code
S
Net shares
-353.0
Price per Share
$327.67
Amount (USD)
$115,667.51
Acquired/Disposed
Disposed
Shares Owned Before
26,053.0
Shares Owned After
25,700.0
Security
Common Stock
Action
Sell
Date
2026-03-02
Code
S
Net shares
-107.0
Price per Share
$328.71
Amount (USD)
$35,171.97
Acquired/Disposed
Disposed
Shares Owned Before
25,700.0
Shares Owned After
25,593.0
Security
Common Stock
Action
Sell
Date
2026-03-02
Code
S
Net shares
-182.0
Price per Share
$329.71
Amount (USD)
$60,007.22
Acquired/Disposed
Disposed
Shares Owned Before
25,593.0
Shares Owned After
25,411.0
Security
Common Stock
Action
Sell
Date
2026-03-02
Code
S
Net shares
-87.0
Price per Share
$330.85
Amount (USD)
$28,783.95
Acquired/Disposed
Disposed
Shares Owned Before
25,411.0
Shares Owned After
25,324.0
Security
Common Stock
Action
Sell
Date
2026-03-02
Code
S
Net shares
-101.0
Price per Share
$331.93
Amount (USD)
$33,524.93
Acquired/Disposed
Disposed
Shares Owned Before
25,324.0
Shares Owned After
25,223.0
Security
Common Stock
Action
Sell
Date
2026-03-02
Code
S
Net shares
-42.0
Price per Share
$332.64
Amount (USD)
$13,970.88
Acquired/Disposed
Disposed
Shares Owned Before
25,223.0
Shares Owned After
25,181.0
Security
Common Stock
Action
Sell
Date
2026-03-03
Code
S
Net shares
-355.0
Price per Share
$316.74
Amount (USD)
$112,442.70
Acquired/Disposed
Disposed
Shares Owned Before
25,181.0
Shares Owned After
24,826.0
Security
Common Stock
Action
Sell
Date
2026-03-03
Code
S
Net shares
-317.0
Price per Share
$319.06
Amount (USD)
$101,142.02
Acquired/Disposed
Disposed
Shares Owned Before
24,826.0
Shares Owned After
24,509.0
Security
Common Stock
Action
Sell
Date
2026-03-03
Code
S
Net shares
-640.0
Price per Share
$320.48
Amount (USD)
$205,107.20
Acquired/Disposed
Disposed
Shares Owned Before
24,509.0
Shares Owned After
23,869.0
Security
Common Stock
Action
Sell
Date
2026-03-03
Code
S
Net shares
-463.0
Price per Share
$321.50
Amount (USD)
$148,854.50
Acquired/Disposed
Disposed
Shares Owned Before
23,869.0
Shares Owned After
23,406.0
Security
Stock Option (right to buy)
Action
Grant
Date
2026-03-02
Code
A
Net shares
+10,480.0
Acquired/Disposed
Acquired
Shares Owned Before
0.0
Shares Owned After
10,480.0
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 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.
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 $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.
4. 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.
5. 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.
6. 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.
7. 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.
8. 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.
9. 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.
10. 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.
11. 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.
12. 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.
13. This transaction was made pursuant to a Rule 10b5-1(c) trading plan adopted by the Reporting Person on November 20, 2025.
14. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $316.45 to $317.34. 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.
15. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $318.71 to $319.16. 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.
16. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $319.97 to $320.71. 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.
17. The price reported represents the weighted average sales price of shares sold in multiple transactions at prices ranging from $321.30 to $321.79. 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.
18. 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.
19. Represents shares held in trust, of which the Reporting Persons spouse is co-trustee. The Reporting Person disclaims beneficial ownership of these shares, and the filing of this report is not an admission that the Reporting Person is the beneficial owner of these securities for purposes of Section 16 or for any other purpose.
20. 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.
ℹ️ Filed under Rule 10b5-1 trading plan
This page is for informational purposes only. While we strive for accuracy, the summary may contain inaccuracies or omissions. Please refer to the official SEC filing for authoritative information. Open the SEC filing.