Biogen Inc.
MX ˙ BMV ˙ US09062X1037
SecurityMX:BIIB / Biogen Inc.
InstitutionComerica Bank
Latest Disclosed Ownership19,475 shares
Latest Disclosed Value $ 3,427,422
Comerica Bank reports 42.16% decrease in ownership of BIIB / Biogen Inc.

On January 29, 2026 - Comerica Bank filed a 13F-HR form disclosing ownership of 19,475 shares of Biogen Inc. (MX:BIIB) valued at $3,427,422 USD as of December 31, 2025. The entity filed a previous 13F-HR on November 14, 2025 disclosing 33,670 shares of Biogen Inc.. This represents a change in shares of -42.16% 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)
2026-01-29 2025-12-31 13F BIOGEN COM 09062X103 19,475 -14,195 -42.16 3,427 -27.33 0.0137
2025-11-14 2025-09-30 13F BIOGEN COM 09062X103 33,670 12,561 59.51 4,716 77.90 0.0177
2025-08-14 2025-06-30 13F BIOGEN COM 09062X103 21,109 -964 -4.37 2,651 -12.22 0.0103
2025-05-14 2025-03-31 13F BIOGEN COM 09062X103 22,073 -11,623 -34.49 3,021 -41.38 0.0127
2025-02-14 2024-12-31 13F/A-1 BIOGEN COM 09062X103 33,696 -5,735 -14.54 5,153 -32.59 0.0208
2025-02-14 2024-12-31 13F BIOGEN COM 09062X103 33,696 -5,735 5,153 0.0173
2024-11-14 2024-09-30 13F BIOGEN COM 09062X103 39,431 -1,467 -3.59 7,643 -19.39 0.0302
2024-08-15 2024-06-30 13F BIOGEN IDEC COMMON 09062X103 40,898 -1,416 -3.35 9,481 3.91 0.0395
2024-05-16 2024-03-31 13F BIOGEN IDEC COMMON 09062X103 42,314 1,210 2.94 9,124 -14.22 0.0393
2024-02-14 2023-12-31 13F BIOGEN IDEC COMMON 09062X103 41,104 3,025 7.94 10,636 8.69 0.0490
2023-11-21 2023-09-30 13F BIOGEN COMMON 09062X103 38,079 38,079 9,787 0.0510
2023-08-22 2023-06-30 13F BIOGEN IDEC COM 09062X103 0 -23,944 -100.00 0 -100.00
2023-01-26 2022-12-31 13F BIOGEN IDEC COM 09062X103 23,944 5,949 33.06 7 -99.88 0.0539
2022-10-28 2022-09-30 13F BIOGEN IDEC COM 09062X103 17,995 590 3.39 4,942 28.90 0.0417
2022-08-02 2022-06-30 13F BIOGEN IDEC COM 09062X103 17,405 1,412 8.83 3,834 8.77 0.0315
2022-04-27 2022-03-31 13F BIOGEN IDEC COM 09062X103 15,993 -201 -1.24 3,525 -2.08 0.0256
2022-02-18 2021-12-31 13F BIOGEN IDEC COM 09062X103 16,194 -5,813 -26.41 3,600 -38.22 0.0265
2021-11-22 2021-09-30 13F BIOGEN IDEC COM 09062X103 22,007 -1,671 -7.06 5,827 -27.33 0.0351
2021-08-26 2021-06-30 13F BIOGEN IDEC COM 09062X103 23,678 -1,971 -7.68 8,018 19.03 0.0479
2021-04-28 2021-03-31 13F BIOGEN IDEC COM 09062X103 25,649 -1,640 -6.01 6,736 -8.39 0.0402
2021-01-28 2020-12-31 13F BIOGEN IDEC COM 09062X103 27,289 -2,437 -8.20 7,353 -6.66 0.0467
2020-10-30 2020-09-30 13F BIOGEN IDEC COM 09062X103 29,726 -935 -3.05 7,878 -8.49 0.0572
2020-07-31 2020-06-30 13F BIOGEN IDEC COM 09062X103 30,661 -1,143 -3.59 8,609 -9.10 0.0663
2020-05-01 2020-03-31 13F BIOGEN IDEC COM 09062X103 31,804 -1,019 -3.10 9,471 3.97 0.0869
2020-02-07 2019-12-31 13F BIOGEN IDEC COM 09062X103 32,823 -2,275 -6.48 9,109 -9.16 0.0690
2019-10-31 2019-09-30 13F BIOGEN IDEC COM 09062X103 35,098 -2,859 -7.53 10,027 15.13 0.0792
2019-08-02 2019-06-30 13F BIOGEN IDEC COM 09062X103 37,957 -3,507 -8.46 8,709 -12.58 0.0697
2019-05-02 2019-03-31 13F BIOGEN IDEC COM 09062X103 41,464 -577 -1.37 9,962 -29.16 0.0808
2019-02-06 2018-12-31 13F BIOGEN IDEC COM 09062X103 42,041 121 0.29 14,062 6.10 0.1194
2018-11-01 2018-09-30 13F BIOGEN IDEC COM 09062X103 41,920 -13,679 -24.60 13,253 -32.85 0.1069
2018-08-01 2018-06-30 13F BIOGEN IDEC COM 09062X103 55,599 -908 -1.61 19,735 31.29 0.1380
2018-05-01 2018-03-31 13F BIOGEN IDEC COM 09062X103 56,507 213 0.38 15,032 -22.93 0.1074
2018-02-02 2017-12-31 13F BIOGEN IDEC COM 09062X103 56,294 -2,288 -3.91 19,505 5.43 0.1299
2017-11-06 2017-09-30 13F BIOGEN IDEC COM 09062X103 58,582 -692 -1.17 18,500 9.63 0.1339
2017-08-03 2017-06-30 13F BIOGEN IDEC COM 09062X103 59,274 -1,116 -1.85 16,875 1.04 0.1263
2017-05-03 2017-03-31 13F BIOGEN IDEC COM 09062X103 60,390 -2,067 -3.31 16,702 -6.09 0.1268
2017-02-08 2016-12-31 13F BIOGEN IDEC COM 09062X103 62,457 2,573 4.30 17,785 -5.54 0.1407
2016-08-11 2016-06-30 13F BIOGEN IDEC COM 09062X103 59,884 -827 -1.36 18,829 15.51 0.1626
2016-05-11 2016-03-31 13F BIOGEN IDEC COM 09062X103 60,711 -1,641 -2.63 16,301 -6.82 0.1456
2016-02-05 2015-12-31 13F BIOGEN IDEC COM 09062X103 62,352 -7,582 -10.84 17,495 -14.27 0.1717
2015-11-12 2015-09-30 13F BIOGEN IDEC COM 09062X103 69,934 -83,204 -54.33 20,408 -67.01 0.1933
2015-08-13 2015-06-30 13F BIOGEN IDEC COM 09062X103 153,138 74,360 94.39 61,858 85.97 0.2656
2015-05-15 2015-03-31 13F BIOGEN IDEC COM 09062X103 78,778 -81,906 -50.97 33,262 -39.02 0.2817
2015-02-13 2014-12-31 13F BIOGEN IDEC COM 09062X103 160,684 77,941 94.20 54,544 99.27 0.2358
2014-10-21 2014-09-30 13F BIOGEN IDEC COM 09062X103 82,743 -6,581 -7.37 27,372 -2.82 0.2417
2014-08-12 2014-06-30 13F BIOGEN IDEC COM 09062X103 89,324 -21,446 -19.36 28,165 -16.87 0.2395
2014-05-15 2014-03-31 13F BIOGEN IDEC COM 09062X103 110,770 2,163 1.99 33,881 11.59 0.2595
2014-02-11 2013-12-31 13F BIOGEN IDEC COM 09062X103 108,607 -17,449 -13.84 30,362 0.04 0.2354
2013-11-12 2013-09-30 13F BIOGEN IDEC COM 09062X103 126,056 -3,341 -2.58 30,350 8.99 0.2112
2013-08-13 2013-06-30 13F/A-1 BIOGEN IDEC COM 09062X103 129,397 129,397 27,847 0.2270
2013-08-08 2013-06-30 13F BIOGEN IDEC COM 09062X103 855,339 184,072
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.