Biogen Inc.
MX ˙ BMV ˙ US09062X1037
SecurityMX:BIIB / Biogen Inc.
InstitutionBessemer Group Inc
Latest Disclosed Ownership3,127 shares
Latest Disclosed Value $ 573
Bessemer Group Inc reports 15.34% increase in ownership of BIIB / Biogen Inc.

On May 6, 2026 - Bessemer Group Inc filed a 13F-HR form disclosing ownership of 3,127 shares of Biogen Inc. (MX:BIIB) valued at $573 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 5, 2026 disclosing 2,711 shares of Biogen Inc..

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)
2026-05-06 2026-03-31 13F BIOGEN SC 09062X103 3,127 416 15.34 1 0.0009
2026-02-05 2025-12-31 13F BIOGEN SC 09062X103 2,711 -61 -2.20 0 0.0007
2025-11-05 2025-09-30 13F BIOGEN SC 09062X103 2,772 -772 -21.78 0 0.0006
2025-08-01 2025-06-30 13F BIOGEN SC 09062X103 3,544 507 16.69 0 0.0007
2025-04-23 2025-03-31 13F BIOGEN SC 09062X103 3,037 729 31.59 0 0.0007
2025-02-13 2024-12-31 13F BIOGEN SC 09062X103 2,308 -384 -14.26 0 0.0006
2024-11-12 2024-09-30 13F BIOGEN SC 09062X103 2,692 -639 -19.18 1 0.0009
2024-08-13 2024-06-30 13F BIOGEN SC 09062X103 3,331 277 9.07 1 0.0014
2024-08-13 2024-03-31 13F/A-1 BIOGEN SC 09062X103 3,054 43 1.43 1 0.0012
2024-05-13 2024-03-31 13F BIOGEN SC 09062X103 3,054 43 1 0.0012
2024-02-09 2023-12-31 13F BIOGEN SC 09062X103 3,011 -2,055 -40.56 1 -100.00 0.0015
2023-11-13 2023-09-30 13F BIOGEN SC 09062X103 5,066 -333 -6.17 1 0.00 0.0029
2023-08-10 2023-06-30 13F BIOGEN SC 09062X103 5,399 1,064 24.54 2 0.00 0.0033
2023-05-10 2023-03-31 13F BIOGEN SC 09062X103 4,335 -55 -1.25 1 0.00 0.0029
2023-02-13 2022-12-31 13F BIOGEN SC 09062X103 4,390 -170 -3.73 1 -99.92 0.0030
2022-11-09 2022-09-30 13F BIOGEN SC 09062X103 4,560 883 24.01 1,217 62.27 0.0032
2022-08-10 2022-06-30 13F BIOGEN SC 09062X103 3,677 -10 -0.27 750 -3.47 0.0019
2022-05-12 2022-03-31 13F BIOGEN SC 09062X103 3,687 854 30.14 777 14.43 0.0016
2022-01-27 2021-12-31 13F BIOGEN SC 09062X103 2,833 695 32.51 679 12.05 0.0014
2021-11-12 2021-09-30 13F BIOGEN SC 09062X103 2,138 -273 -11.32 606 -27.34 0.0013
2021-08-06 2021-06-30 13F BIOGEN SC 09062X103 2,411 259 12.04 834 38.54 0.0018
2021-05-13 2021-03-31 13F BIOGEN SC 09062X103 2,152 -1,844 -46.15 602 -38.45 0.0014
2021-02-09 2020-12-31 13F BIOGEN SC 09062X103 3,996 -887 -18.17 978 -29.44 0.0026
2020-11-12 2020-09-30 13F BIOGEN SC 09062X103 4,883 -3,030 -38.29 1,386 -34.53 0.0041
2020-08-05 2020-06-30 13F BIOGEN SC 09062X103 7,913 4,081 106.50 2,117 74.67 0.0067
2020-04-30 2020-03-31 13F BIOGEN SC 09062X103 3,832 -269 -6.56 1,212 -0.41 0.0049
2020-02-04 2019-12-31 13F BIOGEN SC 09062X103 4,101 482 13.32 1,217 44.37 0.0039
2019-11-07 2019-09-30 13F BIOGEN SC 09062X103 3,619 -190 -4.99 843 -5.39 0.0030
2019-07-19 2019-06-30 13F BIOGEN SC 09062X103 3,809 1,622 74.17 891 72.01 0.0030
2019-05-13 2019-03-31 13F BIOGEN SC 09062X103 2,187 854 64.07 518 29.18 0.0020
2019-05-21 2018-12-31 13F/A-1 BIOGEN SC 09062X103 1,333 381 40.02 401 19.35 0.0017
2019-02-12 2018-12-31 13F BIOGEN SC 09062X103 1,333 381 401 0.0017
2018-11-06 2018-09-30 13F BIOGEN SC 09062X103 952 -40 -4.03 336 16.67 0.0013
2018-07-25 2018-06-30 13F BIOGEN SC 09062X103 992 -80 -7.46 288 -1.71 0.0011
2018-05-10 2018-03-31 13F BIOGEN SC 09062X103 1,072 -19 -1.74 293 -15.56 0.0011
2018-01-30 2017-12-31 13F BIOGEN SC 09062X103 1,091 33 3.12 347 4.83 0.0013
2017-11-03 2017-09-30 13F BIOGEN SC 09062X103 1,058 -340 -24.32 331 -12.66 0.0013
2017-07-27 2017-06-30 13F BIOGEN SC 09062X103 1,398 -3,230 -69.79 379 -70.04 0.0015
2017-05-12 2017-03-31 13F BIOGEN SC 09062X103 4,628 3,126 208.12 1,265 196.95 0.0053
2017-02-07 2016-12-31 13F BIOGEN SC 09062X103 1,502 555 58.61 426 43.43 0.0020
2016-11-10 2016-09-30 13F BIOGEN SC 09062X103 947 -1,181 -55.50 297 -42.22 0.0015
2016-08-11 2016-06-30 13F BIOGEN SC 09062X103 2,128 348 19.55 514 11.02 0.0028
2016-05-11 2016-03-31 13F BIOGEN SC 09062X103 1,780 -7,817 -81.45 463 -84.25 0.0026
2016-02-12 2015-12-31 13F BIOGEN SC 09062X103 9,597 415 4.52 2,940 9.74 0.0164
2015-11-16 2015-09-30 13F BIOGEN SC 09062X103 9,182 5,552 152.95 2,679 82.87 0.0153
2015-08-14 2015-06-30 13F BIOGEN SC 09062X103 3,630 194 5.65 1,465 0.96 0.0077
2015-06-18 2015-03-31 13F/A-1 BIOGEN SC 09062X103 3,436 -2,200 -39.03 1,451 -24.15 0.0074
2015-05-14 2015-03-31 13F BIOGEN SC 09062X103 3,436 1,451
2015-02-17 2014-12-31 13F BIOGEN IDEC SC 09062X103 5,636 2,961 110.69 1,913 116.16 0.0103
2014-12-11 2014-09-30 13F/A-1 BIOGEN IDEC SC 09062X103 2,675 121 4.74 885 9.94 0.0050
2014-11-13 2014-09-30 13F BIOGEN IDEC SC 09062X103 2,675 121 885 0.0056
2014-08-13 2014-06-30 13F BIOGEN IDEC SC 09062X103 2,554 232 9.99 805 13.38 0.0049
2014-05-14 2014-03-31 13F BIOGEN IDEC SC 09062X103 2,322 105 4.74 710 14.70 0.0048
2014-02-18 2013-12-31 13F BIOGEN IDEC SC 09062X103 2,217 -3 -0.14 619 15.92 0.0044
2013-11-08 2013-09-30 13F BIOGEN IDEC SC 09062X103 2,220 -531 -19.30 534 -9.80 0.0043
2013-08-14 2013-06-30 13F BIOGEN IDEC SC 09062X103 2,751 2,751 592 0.0053
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.