Alnylam Pharmaceuticals, Inc.
DE ˙ XTRA ˙ US02043Q1076
251,80 € ↑6,70 (2,73%)
2026-06-03
DEL PRIS
SecurityDE:DUL / Alnylam Pharmaceuticals, Inc.
InstitutionAsset Management One Co., Ltd.
Latest Disclosed Ownership57,709 shares
Latest Disclosed Value $ 19,094,177
Asset Management One Co., Ltd. reports 11.47% decrease in ownership of DUL / Alnylam Pharmaceuticals, Inc.

On May 8, 2026 - Asset Management One Co., Ltd. filed a 13F-HR form disclosing ownership of 57,709 shares of Alnylam Pharmaceuticals, Inc. (DE:DUL) valued at $16,487,461 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 27, 2026 disclosing 65,187 shares of Alnylam Pharmaceuticals, Inc.. This represents a change in shares of -11.47% during the quarter. The current value of the position is $14,531,126 USD.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

Upgrade to unlock premium data and export to Excel .

Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date		 Effective
Date		Form Security Class ID Avg Price
Paid (Est)		 Reported
Shares		 ΔShares ΔShares
(%)		 Reported
Value
(x1000)		 ΔValue
(%)		 Alloc
(%)		 ΔAlloc ΔAlloc (%) Cost Basis
(x1000)		 Unrealized
Gain/Loss
(x1000)
2026-05-08 2026-03-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 57,709 -7,478 -11.47 19,094 -26.55 0.0563
2026-01-27 2025-12-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 65,187 -4,423 -6.35 25,997 -18.10 0.0723
2025-10-22 2025-09-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 69,610 300 0.43 31,742 40.45 0.0920
2025-07-31 2025-06-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 69,310 853 1.25 22,601 22.27 0.0709
2025-04-23 2025-03-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 68,457 3,094 4.73 18,485 18.84 0.0639
2025-01-30 2024-12-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 65,363 -2,590 -3.81 15,554 -16.77 0.0534
2024-10-30 2024-09-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 67,953 2,257 3.44 18,689 17.07 0.0665
2024-07-18 2024-06-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 65,696 -2,223 -3.27 15,964 57.28 0.0611
2024-05-02 2024-03-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 67,919 -1,415 -2.04 10,150 -25.20 0.0391
2024-01-24 2023-12-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 69,334 20,268 41.31 13,569 56.16 0.0546
2023-10-19 2023-09-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 49,066 -339 -0.69 8,690 -7.40 0.0387
2023-07-31 2023-06-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 49,405 1,027 2.12 9,384 -3.18 0.0397
2023-04-25 2023-03-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 48,378 546 1.14 9,691 -14.88 0.0439
2023-02-06 2022-12-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 47,832 -1,025 -2.10 11,386 16.42 0.0555
2022-11-04 2022-09-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 48,857 -2,607 -5.07 9,779 30.28 0.0498
2022-07-29 2022-06-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 51,464 1,231 2.45 7,506 -8.49 0.0352
2022-05-13 2022-03-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 50,233 -2,079 -3.97 8,202 -7.80 0.0320
2022-02-09 2021-12-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 52,312 -336 -0.64 8,896 -10.50 0.0310
2021-11-02 2021-09-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 52,648 -298 -0.56 9,940 10.75 0.0381
2021-08-03 2021-06-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 52,946 -1,848 -3.37 8,975 16.02 0.0334
2021-05-14 2021-03-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 54,794 -48 -0.09 7,736 8.06 0.0307
2021-02-12 2020-12-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 54,842 -765 -1.38 7,159 -11.61 0.0295
2020-11-13 2020-09-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 55,607 -2,669 -4.58 8,099 -6.17 0.0372
2020-08-14 2020-06-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 58,276 -16 -0.03 8,632 36.09 0.0425
2020-05-14 2020-03-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 58,292 -1,440 -2.41 6,343 -7.79 0.0370
2020-02-14 2019-12-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 59,732 1,809 3.12 6,879 47.65 0.0310
2019-11-14 2019-09-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 57,923 8,799 17.91 4,659 30.72 0.0224
2019-08-14 2019-06-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 49,124 -564 -1.14 3,564 -23.26 0.0175
2019-05-15 2019-03-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 49,688 -90,193 -64.48 4,644 -54.35 0.0251
2019-02-13 2018-12-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 139,881 -89 -0.06 10,173 -17.06 0.0242
2018-11-14 2018-09-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 139,970 1,280 0.92 12,265 -10.16 0.0252
2018-08-14 2018-06-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 138,690 2,858 2.10 13,652 -15.61 0.0298
2018-05-14 2018-03-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 135,832 122 0.09 16,177 -6.27 0.0364
2018-02-14 2017-12-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 135,710 135,710 17,260 0.0381
2017-05-02 2016-12-31 13F/A-1 ALNYLAM PHARMACEUTICALS Com 02043Q107 0 -56,343 -100.00 0 -100.00
2016-11-07 2016-09-30 13F ALNYLAM PHARMACEUTICALS Com 02043Q107 56,343 11,465 25.55 3,935 57.78 0.0585
2016-08-03 2016-06-30 13F ALNYLAM PHARMACEUTICALS Com 02043Q107 44,878 38,103 562.41 2,494 517.33 0.0374
2016-05-05 2016-03-31 13F ALNYLAM PHARMACEUTICALS Com 02043Q107 6,775 0 0.00 404 -36.48 0.0059
2016-01-28 2015-12-31 13F ALNYLAM PHARMACEUTICALS Com 02043Q107 6,775 0 0.00 636 20.68 0.0095
2015-11-12 2015-09-30 13F ALNYLAM PHARMACEUTICALS Com 02043Q107 6,775 0 0.00 527 -32.35 0.0080
2015-08-06 2015-06-30 13F ALNYLAM PHARMACEUTICALS Com 02043Q107 6,775 2,792 70.10 779 204.30 0.0108
2014-05-05 2014-03-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 3,983 3,983 256 0.0040
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.