Biogen Inc.
MX ˙ BMV ˙ US09062X1037
SecurityMX:BIIB / Biogen Inc.
InstitutionCommonwealth Equity Services, Llc
Latest Disclosed Ownership18,394 shares
Latest Disclosed Value $ 3,237,115
Commonwealth Equity Services, Llc reports 2.09% increase in ownership of BIIB / Biogen Inc.

On February 12, 2026 - Commonwealth Equity Services, Llc filed a 13F-HR form disclosing ownership of 18,394 shares of Biogen Inc. (MX:BIIB) valued at $3,237,115 USD as of December 31, 2025. The entity filed a previous 13F-HR on October 22, 2025 disclosing 18,017 shares of Biogen Inc.. This represents a change in shares of 2.09% during the quarter.

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)
2026-02-12 2025-12-31 13F BIOGEN COM 09062X103 18,394 377 2.09 3,237 161,750.00 0.0043
2025-10-22 2025-09-30 13F BIOGEN COM 09062X103 18,017 -10,534 -36.90 3 -33.33 0.0033
2025-08-06 2025-06-30 13F BIOGEN COM 09062X103 28,551 1,071 3.90 4 0.00 0.0047
2025-05-09 2025-03-31 13F BIOGEN COM 09062X103 27,480 1,188 4.52 4 -25.00 0.0053
2025-02-10 2024-12-31 13F BIOGEN COM 09062X103 26,292 -2,051 -7.24 4 -20.00 0.0059
2024-10-18 2024-09-30 13F BIOGEN COM 09062X103 28,343 -103 -0.36 5 -16.67 0.0083
2024-07-31 2024-06-30 13F BIOGEN COM 09062X103 28,446 6,259 28.21 7 50.00 0.0104
2024-04-29 2024-03-31 13F BIOGEN COM 09062X103 22,187 -425 -1.88 5 -20.00 0.0079
2024-02-06 2023-12-31 13F BIOGEN COM 09062X103 22,612 -804 -3.43 6 -16.67 0.0107
2023-10-23 2023-09-30 13F BIOGEN COM 09062X103 23,416 433 1.88 6 0.00 0.0125
2023-08-10 2023-06-30 13F BIOGEN COM 09062X103 22,983 -726 -3.06 7 0.00 0.0133
2023-05-11 2023-03-31 13F BIOGEN COM 09062X103 23,709 -8,731 -26.91 7 -25.00 0.0138
2023-02-07 2022-12-31 13F BIOGEN COM 09062X103 32,440 9,405 40.83 9 -99.87 0.0216
2022-11-14 2022-09-30 13F BIOGEN COM 09062X103 23,035 -321 -1.37 6,150 29.12 0.0158
2022-07-19 2022-06-30 13F BIOGEN COM 09062X103 23,356 -1,641 -6.56 4,763 -9.52 0.0124
2022-05-04 2022-03-31 13F BIOGEN COM 09062X103 24,997 920 3.82 5,264 -8.86 0.0120
2022-01-31 2021-12-31 13F BIOGEN COM 09062X103 24,077 -3,148 -11.56 5,776 -25.03 0.0130
2021-10-29 2021-09-30 13F BIOGEN COM 09062X103 27,225 -485 -1.75 7,704 -19.71 0.0193
2021-08-11 2021-06-30 13F BIOGEN COM 09062X103 27,710 5,620 25.44 9,595 55.28 0.0244
2021-05-04 2021-03-31 13F BIOGEN COM 09062X103 22,090 -1,003 -4.34 6,179 9.29 0.0175
2021-02-11 2020-12-31 13F BIOGEN COM 09062X103 23,093 -2,175 -8.61 5,654 -21.12 0.0170
2020-11-05 2020-09-30 13F BIOGEN COM 09062X103 25,268 -1,808 -6.68 7,168 -1.05 0.0245
2020-08-12 2020-06-30 13F BIOGEN COM 09062X103 27,076 2,328 9.41 7,244 -7.48 0.0273
2020-05-11 2020-03-31 13F BIOGEN COM 09062X103 24,748 -1,823 -6.86 7,830 -0.68 0.0365
2020-02-05 2019-12-31 13F BIOGEN COM 09062X103 26,571 2,216 9.10 7,884 39.05 0.0300
2019-10-30 2019-09-30 13F BIOGEN COM 09062X103 24,355 -1,679 -6.45 5,670 -6.87 0.0242
2019-07-19 2019-06-30 13F BIOGEN COM 09062X103 26,034 -3,905 -13.04 6,088 -13.97 0.0268
2019-05-13 2019-03-31 13F BIOGEN COM 09062X103 29,939 2,729 10.03 7,077 -13.57 0.0327
2019-02-11 2018-12-31 13F BIOGEN COM 09062X103 27,210 -1,095 -3.87 8,188 -18.12 0.0435
2018-11-06 2018-09-30 13F BIOGEN COM 09062X103 28,305 282 1.01 10,000 22.96 0.0479
2018-07-31 2018-06-30 13F BIOGEN COM 09062X103 28,023 -81 -0.29 8,133 5.69 0.0425
2018-05-14 2018-03-31 13F BIOGEN COM 09062X103 28,104 144 0.52 7,695 -13.61 0.0418
2018-02-12 2017-12-31 13F BIOGEN COM 09062X103 27,960 27,960 8,907 0.0487
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.