Biogen Inc.
US ˙ NasdaqGS ˙ US09062X1037

SecurityBIIB / Biogen Inc.
InstitutionEngineers Gate Manager LP
Latest Disclosed Ownership1,558 shares
Latest Disclosed Value $ 285,628
Engineers Gate Manager LP ownership in BIIB / Biogen Inc.

On May 15, 2026 - Engineers Gate Manager LP filed a 13F-HR form disclosing ownership of 1,558 shares of Biogen Inc. (US:BIIB) valued at $285,628 USD as of March 31, 2026. The entity filed a previous 13F-HR on November 14, 2025 disclosing 0 shares of Biogen Inc.. The current value of the position is $305,306 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 BIOGEN COM 09062X103 1,558 1,558 286 0.0036
2025-11-14 2025-09-30 13F BIOGEN COM 09062X103 0 -33,008 -100.00 0 -100.00
2025-08-14 2025-06-30 13F BIOGEN COM 09062X103 33,008 -43,950 -57.11 4,145 -60.64 0.0516
2025-05-15 2025-03-31 13F BIOGEN COM 09062X103 76,958 48,915 174.43 10,531 145.57 0.1775
2025-02-14 2024-12-31 13F BIOGEN COM 09062X103 28,043 10,051 55.86 4,288 22.97 0.0746
2024-11-14 2024-09-30 13F BIOGEN COM 09062X103 17,992 17,992 3,488 0.0681
2024-08-14 2024-06-30 13F BIOGEN COM 09062X103 0 -39,840 -100.00 0 -100.00
2024-05-15 2024-03-31 13F BIOGEN COM 09062X103 39,840 39,840 8,591 0.2262
2023-08-14 2023-06-30 13F BIOGEN COM 09062X103 0 -3,462 -100.00 0 -100.00
2023-05-15 2023-03-31 13F BIOGEN COM 09062X103 3,462 -2,834 -45.01 963 -44.81 0.0402
2023-02-14 2022-12-31 13F BIOGEN COM 09062X103 6,296 3,647 137.67 1,743 146.53 0.1047
2022-11-14 2022-09-30 13F BIOGEN COM 09062X103 2,649 -10,982 -80.57 707 -74.57 0.0440
2022-08-15 2022-06-30 13F BIOGEN COM 09062X103 13,631 2,295 20.25 2,780 16.46 0.1019
2022-05-16 2022-03-31 13F BIOGEN COM 09062X103 11,336 10,095 813.46 2,387 701.01 0.0934
2022-02-14 2021-12-31 13F BIOGEN COM 09062X103 1,241 -1,474 -54.29 298 -61.20 0.0134
2021-11-15 2021-09-30 13F BIOGEN COM 09062X103 2,715 55 2.07 768 -16.61 0.0438
2021-08-16 2021-06-30 13F BIOGEN COM 09062X103 2,660 2,660 921 0.0592
2021-05-17 2021-03-31 13F BIOGEN COM 09062X103 0 -12,908 -100.00 0 -100.00
2021-02-16 2020-12-31 13F BIOGEN COM 09062X103 12,908 11,011 580.44 3,161 487.55 0.1371
2020-11-16 2020-09-30 13F BIOGEN COM 09062X103 1,897 -7,041 -78.78 538 -77.50 0.0252
2020-08-17 2020-06-30 13F BIOGEN COM 09062X103 8,938 7,908 767.77 2,391 633.44 0.1217
2020-05-15 2020-03-31 13F BIOGEN COM 09062X103 1,030 -15,174 -93.64 326 -93.22 0.0235
2020-02-14 2019-12-31 13F BIOGEN COM 09062X103 16,204 3,608 28.64 4,808 63.93 0.2114
2019-11-14 2019-09-30 13F BIOGEN COM 09062X103 12,596 12,596 -22.27 2,933 -39.00 0.1490
2019-08-14 2019-06-30 13F BIOGEN COM 09062X103 0 -10,300 -100.00 0 -100.00
2019-05-15 2019-03-31 13F BIOGEN COM 09062X103 10,300 10,300 2,435 0.1475
2017-08-10 2017-06-30 13F BIOGEN COM 09062X103 0 -5,300 -100.00 0 -100.00
2017-05-05 2017-03-31 13F BIOGEN COM 09062X103 5,300 5,300 1,449 0.1439
2015-08-14 2015-06-30 13F BIOGEN COM 09062X103 0 -1,759 -100.00 0 -100.00
2015-05-15 2015-03-31 13F BIOGEN COM 09062X103 1,759 1,124 177.01 743 243.98 0.0988
2015-02-17 2014-12-31 13F BIOGEN IDEC COM 09062X103 635 635 216 0.0615
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.