Alnylam Pharmaceuticals, Inc.
DE ˙ XTRA ˙ US02043Q1076
251,80 € ↑6,70 (2,73%)
2026-06-03
DEL PRIS
SecurityDE:DUL / Alnylam Pharmaceuticals, Inc.
InstitutionBrandywine Managers, Llc
Latest Disclosed Ownership3,168 shares
Latest Disclosed Value $ 1,048,196
Brandywine Managers, Llc reports 12.44% decrease in ownership of DUL / Alnylam Pharmaceuticals, Inc.

On May 14, 2026 - Brandywine Managers, Llc filed a 13F-HR form disclosing ownership of 3,168 shares of Alnylam Pharmaceuticals, Inc. (DE:DUL) valued at $905,098 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 3,618 shares of Alnylam Pharmaceuticals, Inc.. This represents a change in shares of -12.44% during the quarter. The current value of the position is $797,702 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.

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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)
2026-05-14 2026-03-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 3,168 -450 -12.44 1,048 -27.12 0.6169
2026-02-13 2025-12-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 3,618 -100 -2.69 1,439 -15.16 0.7113
2025-11-14 2025-09-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 3,718 -500 -11.85 1,695 23.27 1.6263
2025-08-14 2025-06-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 4,218 -130 -2.99 1,375 17.12 1.3669
2025-05-15 2025-03-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 4,348 0 0.00 1,174 14.76 1.4085
2025-02-13 2024-12-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 4,348 0 0.00 1,023 -14.39 1.0781
2024-11-14 2024-09-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 4,348 0 0.00 1,196 13.16 1.2855
2024-08-14 2024-06-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 4,348 0 0.00 1,057 62.71 1.1175
2024-05-15 2024-03-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 4,348 0 0.00 650 -22.00 0.6414
2024-02-14 2023-12-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 4,348 -260 -5.64 832 1.96 0.9111
2023-11-14 2023-09-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 4,608 0 0.00 816 -6.74 1.3770
2023-08-14 2023-06-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 4,608 0 0.00 875 -5.20 0.5778
2023-05-15 2023-03-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 4,608 0 0.00 923 -15.71 0.6561
2023-02-14 2022-12-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 4,608 0 0.00 1,095 18.76 3.8264
2022-11-14 2022-09-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 4,608 0 0.00 922 37.20 3.0328
2022-08-15 2022-06-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 4,608 0 0.00 672 -10.64 1.6467
2022-05-13 2022-03-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 4,608 0 0.00 752 -3.71 1.2972
2022-02-10 2021-12-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 4,608 0 0.00 781 -10.23 0.8850
2021-11-15 2021-09-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 4,608 0 0.00 870 11.40 0.9083
2021-08-16 2021-06-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 4,608 0 0.00 781 19.97 0.8907
2021-05-13 2021-03-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 4,608 1,708 58.90 651 72.68 0.8652
2021-02-12 2020-12-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 2,900 0 0.00 377 -10.66 0.5185
2020-11-16 2020-09-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 2,900 0 0.00 422 -1.86 0.8007
2020-08-14 2020-06-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 2,900 0 0.00 430 36.08 1.7657
2020-05-15 2020-03-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 2,900 0 0.00 316 -5.39 0.1111
2020-02-13 2019-12-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 2,900 -200 -6.45 334 34.14 0.1001
2019-11-13 2019-09-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 3,100 0 0.00 249 10.67 0.0833
2019-08-13 2019-06-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 3,100 -900 -22.50 225 -39.84 0.0843
2019-05-14 2019-03-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 4,000 -200 -4.76 374 22.22 0.1499
2019-02-12 2018-12-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 4,200 4,200 306 0.1443
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.