Alnylam Pharmaceuticals, Inc.
US ˙ NasdaqGS ˙ US02043Q1076

SecurityALNY / Alnylam Pharmaceuticals, Inc.
InstitutionKBC Group NV
Latest Disclosed Ownership20,524 shares
Latest Disclosed Value $ 6,791
KBC Group NV reports 94.11% decrease in ownership of ALNY / Alnylam Pharmaceuticals, Inc.

On May 7, 2026 - KBC Group NV filed a 13F-HR form disclosing ownership of 20,524 shares of Alnylam Pharmaceuticals, Inc. (US:ALNY) valued at $6,790,776 USD as of March 31, 2026. The entity filed a previous 13F-HR on January 26, 2026 disclosing 348,194 shares of Alnylam Pharmaceuticals, Inc.. This represents a change in shares of -94.11% during the quarter. The current value of the position is $6,004,912 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)
2026-05-07 2026-03-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 20,524 -327,670 -94.11 7 -95.65 0.0088
2026-01-26 2025-12-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 348,194 74,842 27.38 138 11.29 0.3157
2026-01-20 2025-09-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 273,352 79,802 41.23 125 96.83 0.2989
2025-08-08 2025-06-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 193,550 174,238 902.23 63 1,160.00 0.1705
2025-04-25 2025-03-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 19,312 -10,714 -35.68 5 -28.57 0.0162
2025-01-22 2024-12-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 30,026 5,460 22.23 7 16.67 0.0195
2024-11-06 2024-09-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 24,566 9,470 62.73 7 100.00 0.0204
2024-07-17 2024-06-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 15,096 0 0.00 4 50.00 0.0111
2024-05-08 2024-03-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 15,096 1,187 8.53 2 0.00 0.0072
2024-02-13 2023-12-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 13,909 -1,601 -10.32 3 0.00 0.0094
2024-02-15 2023-09-30 13F/A-1 ALNYLAM PHARMACEUTICALS COM 02043Q107 15,510 1,390 9.84 3 0.00 0.0112
2023-11-22 2023-09-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 13,943 0 3 0.0110
2024-02-15 2023-06-30 13F/A-1 ALNYLAM PHARMACEUTICALS COM 02043Q107 14,120 -13,886 -49.58 3 -60.00 0.0110
2023-07-28 2023-06-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 13,943 -13,886 3 0.0110
2024-02-14 2023-03-31 13F/A-1 ALNYLAM PHARMACEUTICALS COM 02043Q107 28,006 21,629 339.17 6 400.00 0.0238
2023-05-04 2023-03-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 27,829 20,172 6 0.0263
2024-02-14 2022-12-31 13F/A-1 ALNYLAM PHARMACEUTICALS COM 02043Q107 6,377 -1,449 -18.52 2 0.00 0.0073
2023-02-13 2022-12-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 7,657 -169 2 0.0000
2024-02-15 2022-09-30 13F/A-1 ALNYLAM PHARMACEUTICALS COM 02043Q107 7,826 172 2.25 2 0.00 0.0081
2022-11-08 2022-09-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 7,657 3 1,533 0.0080
2024-02-14 2022-06-30 13F/A-1 ALNYLAM PHARMACEUTICALS COM 02043Q107 7,654 215 2.89 1 0.00 0.0056
2022-07-26 2022-06-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 7,439 0 1,085 0.0055
2024-02-14 2022-03-31 13F/A-1 ALNYLAM PHARMACEUTICALS COM 02043Q107 7,439 200 2.76 1 0.00 0.0048
2022-05-06 2022-03-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 7,439 200 1,215 0.0045
2024-02-14 2021-12-31 13F/A-1 ALNYLAM PHARMACEUTICALS COM 02043Q107 7,239 -7,610 -51.25 1 -99.96 0.0041
2022-02-03 2021-12-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 7,239 -7,610 1,228 0.0038
2021-11-10 2021-09-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 14,849 827 5.90 2,804 17.96 0.0103
2022-02-15 2021-06-30 13F/A-1 ALNYLAM PHARMACEUTICALS COM 02043Q107 14,022 4,453 46.54 2,377 75.94 0.0086
2021-08-11 2021-06-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 14,022 4,453 2,377 0.0086
2022-02-14 2021-03-31 13F/A-1 ALNYLAM PHARMACEUTICALS COM 02043Q107 9,569 0 0.00 1,351 -89.14 0.0055
2021-04-26 2021-03-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 9,569 0 1,351 0.0055
2022-02-14 2020-12-31 13F/A-1 ALNYLAM PHARMACEUTICALS COM 02043Q107 9,569 0 0.00 12,437 792.82 0.0059
2021-02-10 2020-12-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 9,569 0 1,244 0.0057
2022-02-14 2020-09-30 13F/A-1 ALNYLAM PHARMACEUTICALS COM 02043Q107 9,569 -15,159 -61.30 1,393 -61.96 0.0082
2020-10-28 2020-09-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 9,569 -15,159 1,393 0.0082
2022-02-14 2020-06-30 13F/A-1 ALNYLAM PHARMACEUTICALS COM 02043Q107 24,728 11,659 89.21 3,662 157.34 0.0242
2020-08-10 2020-06-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 24,728 11,659 3,662 0.0245
2020-05-04 2020-03-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 13,069 2,058 18.69 1,423 12.22 0.0119
2020-02-11 2019-12-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 11,011 345 3.23 1,268 47.96 0.0080
2019-11-07 2019-09-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 10,666 10,601 16,309.23 857 17,040.00 0.0063
2019-12-03 2019-06-30 13F/A-2 ALNYLAM PHARMACEUTICALS COM 02043Q107 65 0 0.00 5 -16.67 0.0434
2019-08-08 2019-06-30 13F/A-1 ALNYLAM PHARMACEUTICALS COM 02043Q107 7,666 7,601 556 0.0043
2019-07-30 2019-06-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 7,666 0 556
2019-12-03 2019-03-31 13F/A-2 ALNYLAM PHARMACEUTICALS COM 02043Q107 65 0 0.00 6 20.00 0.0545
2019-08-07 2019-03-31 13F/A-1 ALNYLAM PHARMACEUTICALS COM 02043Q107 7,666 7,601 716 0.0059
2019-05-10 2019-03-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 7,666 0 716
2019-12-03 2018-12-31 13F/A-1 ALNYLAM PHARMACEUTICALS COM 02043Q107 65 0 0.00 5 -16.67 0.0584
2019-01-31 2018-12-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 7,666 0 559 6,227.1765
2019-12-03 2018-09-30 13F/A-1 ALNYLAM PHARMACEUTICALS COM 02043Q107 65 0 0.00 6 0.00 0.0592
2018-11-14 2018-09-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 7,666 7,601 671 5,075.7509
2019-12-03 2018-06-30 13F/A-1 ALNYLAM PHARMACEUTICALS COM 02043Q107 65 0 0.00 6 -25.00 0.0663
2018-08-03 2018-06-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 7,666 0 755 6,573.1915
2019-12-03 2018-03-31 13F/A-2 ALNYLAM PHARMACEUTICALS COM 02043Q107 65 -7,601 -99.15 8 -99.18 0.0853
2018-08-03 2018-03-31 13F/A-1 ALNYLAM PHARMACEUTICALS COM 02043Q107 7,666 7,601 913 0.0084
2018-05-09 2018-03-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 7,666 0 913
2018-08-03 2017-12-31 13F/A-1 ALNYLAM PHARMACEUTICALS COM 02043Q107 7,666 6,719 709.50 974 777.48 0.0083
2018-02-07 2017-12-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 7,666 6,719 974
2017-11-13 2017-09-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 947 0 0.00 111 46.05 0.0010
2017-08-04 2017-06-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 947 0 0.00 76 55.10 0.0007
2017-05-10 2017-03-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 947 0 0.00 49 40.00 0.0004
2017-02-16 2016-12-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 947 -21,753 -95.83 35 -97.73 0.0003
2016-11-03 2016-09-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 22,700 18,231 407.94 1,539 520.56 0.0182
2016-08-03 2016-06-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 4,469 0 0.00 248 -11.74 0.0035
2016-05-11 2016-03-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 4,469 0 0.00 281 -33.25 0.0047
2016-02-11 2015-12-31 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 4,469 -1,100 -19.75 421 -6.03 0.0078
2015-11-12 2015-09-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 5,569 -7,552 -57.56 448 -71.52 0.0090
2015-12-16 2015-06-30 13F/A-1 ALNYLAM PHARMACEUTICALS COM 02043Q107 13,121 13,121 0.00 1,573 0.0202
2015-07-31 2015-06-30 13F ALNYLAM PHARMACEUTICALS COM 02043Q107 13,121 1,573
2015-12-16 2015-03-31 13F/A-1 ALNYLAM PHARMACEUTICALS COM 02043Q107 0 0 0 0.0000
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.