Alnylam Pharmaceuticals, Inc.
US ˙ NasdaqGS ˙ US02043Q1076

SecurityALNY / Alnylam Pharmaceuticals, Inc.
InstitutionEngineers Gate Manager LP
Latest Disclosed Ownership32,502 shares
Latest Disclosed Value $ 10,753,936
Engineers Gate Manager LP reports 60.91% increase in ownership of ALNY / Alnylam Pharmaceuticals, Inc.

On May 15, 2026 - Engineers Gate Manager LP filed a 13F-HR form disclosing ownership of 32,502 shares of Alnylam Pharmaceuticals, Inc. (US:ALNY) valued at $10,753,937 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 20,199 shares of Alnylam Pharmaceuticals, Inc.. This represents a change in shares of 60.91% during the quarter. The current value of the position is $9,509,435 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)
2026-05-15 2026-03-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 32,502 12,303 60.91 10,754 33.88 0.1344
2026-02-17 2025-12-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 20,199 -23,650 -53.94 8,032 -59.83 0.0953
2025-11-14 2025-09-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 43,849 11,219 34.38 19,995 87.92 0.2289
2025-08-14 2025-06-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 32,630 7,238 28.51 10,640 55.19 0.1324
2025-05-15 2025-03-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 25,392 -8,505 -25.09 6,856 -14.04 0.1156
2025-02-14 2024-12-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 33,897 22,034 185.74 7,976 144.51 0.1388
2024-11-14 2024-09-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 11,863 4,789 67.70 3,263 89.87 0.0637
2024-08-14 2024-06-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 7,074 -17,649 -71.39 1,719 -53.49 0.0388
2024-05-15 2024-03-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 24,723 7,292 41.83 3,695 10.73 0.0973
2024-02-14 2023-12-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 17,431 17,431 3,336 0.0953
2023-11-14 2023-09-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 0 -5,286 -100.00 0 -100.00
2023-08-14 2023-06-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 5,286 -909 -14.67 1,004 -19.03 0.0380
2023-05-15 2023-03-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 6,195 6,195 1,241 0.0518
2023-02-14 2022-12-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 0 -1,957 -100.00 0 -100.00
2022-11-14 2022-09-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 1,957 -3,467 -63.92 392 -50.44 0.0244
2022-08-15 2022-06-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 5,424 5,424 791 0.0290
2022-05-16 2022-03-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 0 -1,990 -100.00 0 -100.00
2022-02-14 2021-12-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 1,990 856 75.49 337 57.48 0.0152
2021-11-15 2021-09-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 1,134 -14,830 -92.90 214 -92.09 0.0122
2021-08-16 2021-06-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 15,964 13,054 448.59 2,706 558.39 0.1740
2021-05-17 2021-03-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 2,910 420 16.87 411 26.85 0.0204
2021-02-16 2020-12-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 2,490 1,090 77.86 324 58.82 0.0140
2020-11-16 2020-09-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 1,400 -2,100 -60.00 204 -60.62 0.0096
2020-08-17 2020-06-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 3,500 3,500 518 0.0264
2020-05-15 2020-03-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 0 -3,260 -100.00 0 -100.00
2020-02-14 2019-12-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 3,260 3,260 375 0.0165
2016-02-05 2015-12-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 0 -4,600 -100.00 0 -100.00
2015-11-16 2015-09-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 4,600 2,100 84.00 370 23.33 0.0315
2015-08-14 2015-06-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 2,500 2,500 300 0.0294
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.