Biogen Inc.
DE ˙ DB ˙ US09062X1037
170,90 € ↑8,70 (5,36%)
2026-06-04
CENA AKCJI
SecurityDE:IDP / Biogen Inc.
InstitutionJanus Henderson Group Plc
Latest Disclosed Ownership18,975 shares
Latest Disclosed Value $ 3,478,118
Janus Henderson Group Plc reports 6.31% decrease in ownership of IDP / Biogen Inc.

On May 18, 2026 - Janus Henderson Group Plc filed a 13F-HR/A form disclosing ownership of 18,975 shares of Biogen Inc. (DE:IDP) valued at $2,945,869 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 20,252 shares of Biogen Inc.. This represents a change in shares of -6.31% during the quarter. The current value of the position is $3,242,828 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)
2026-05-18 2026-03-31 13F/A-1 BIOGEN COM 09062X103 18,975 -1,277 -6.31 3,478 -2.41 0.0006
2026-05-15 2026-03-31 13F BIOGEN COM 09062X103 18,975 -1,277 -6.31 3,478 -2.41 0.0006
2026-02-17 2025-12-31 13F BIOGEN COM 09062X103 20,252 1,992 10.91 3,564 39.38 0.0016
2025-11-14 2025-09-30 13F BIOGEN COM 09062X103 18,260 0 0.00 2,558 11.56 0.0012
2025-08-14 2025-06-30 13F BIOGEN COM 09062X103 18,260 -2,568 -12.33 2,293 -20.50 0.0011
2025-05-15 2025-03-31 13F BIOGEN COM 09062X103 20,828 1,065 5.39 2,884 -4.60 0.0016
2025-02-14 2024-12-31 13F BIOGEN COM 09062X103 19,763 -3,266 -14.18 3,022 -32.26 0.0015
2024-11-14 2024-09-30 13F BIOGEN COM 09062X103 23,029 1,900 8.99 4,462 -9.03 0.0023
2024-08-14 2024-06-30 13F BIOGEN COM 09062X103 21,129 -14,030 -39.90 4,904 -35.30 0.0026
2024-05-15 2024-03-31 13F BIOGEN COM 09062X103 35,159 13,985 66.05 7,581 38.32 0.0041
2024-02-14 2023-12-31 13F BIOGEN COM 09062X103 21,174 86 0.41 5,481 1.11 0.0033
2023-11-14 2023-09-30 13F BIOGEN COM 09062X103 21,088 1,007 5.01 5,421 -5.23 0.0035
2023-08-14 2023-06-30 13F BIOGEN COM 09062X103 20,081 -1,165 -5.48 5,719 -3.20 0.0036
2023-05-15 2023-03-31 13F BIOGEN COM 09062X103 21,246 2,251 11.85 5,908 12.34 0.0039
2023-02-14 2022-12-31 13F BIOGEN COM 09062X103 18,995 2,334 14.01 5,259 18.21 0.0038
2023-01-13 2022-09-30 13F/A-1 BIOGEN COM 09062X103 16,661 -1,641 -8.97 4,449 19.18 0.0033
2022-11-14 2022-09-30 13F BIOGEN COM 09062X103 16,661 -1,641 4,449 0.0033
2022-08-15 2022-06-30 13F BIOGEN COM 09062X103 18,302 -340,693 -94.90 3,733 -95.06 0.0026
2022-05-16 2022-03-31 13F BIOGEN COM 09062X103 358,995 57,550 19.09 75,607 4.54 0.0365
2022-02-14 2021-12-31 13F BIOGEN COM 09062X103 301,445 164,593 120.27 72,324 86.75 0.0302
2021-11-16 2021-09-30 13F BIOGEN COM 09062X103 136,852 47,905 53.86 38,727 25.71 0.0169
2021-08-16 2021-06-30 13F BIOGEN COM 09062X103 88,947 14,746 19.87 30,806 48.38 0.0132
2021-05-17 2021-03-31 13F BIOGEN COM 09062X103 74,201 -37,796 -33.75 20,761 -24.28 0.0095
2021-02-16 2020-12-31 13F BIOGEN COM 09062X103 111,997 -7,933 -6.61 27,418 -19.40 0.0127
2020-11-16 2020-09-30 13F BIOGEN COM 09062X103 119,930 -7,117 -5.60 34,016 0.09 0.0177
2020-08-14 2020-06-30 13F BIOGEN COM 09062X103 127,047 47,633 59.98 33,986 35.27 0.0191
2020-05-14 2020-03-31 13F BIOGEN COM 09062X103 79,414 -2,593 -3.16 25,125 3.26 0.0173
2020-02-18 2019-12-31 13F BIOGEN COM 09062X103 82,007 2,669 3.36 24,331 31.70 0.0125
2019-11-14 2019-09-30 13F BIOGEN COM 09062X103 79,338 -2,057 -2.53 18,475 -2.95 0.0100
2019-07-31 2019-06-30 13F BIOGEN COM 09062X103 81,395 3,281 4.20 19,036 3.11 0.0104
2019-04-30 2019-03-31 13F BIOGEN COM 09062X103 78,114 -359,200 -82.14 18,462 -85.97 0.0102
2019-02-06 2018-12-31 13F BIOGEN COM 09062X103 437,314 -78,806 -15.27 131,595 -27.84 0.0839
2018-11-09 2018-09-30 13F BIOGEN COM 09062X103 516,120 -1,079,866 -67.66 182,353 -60.63 0.0974
2018-08-10 2018-06-30 13F BIOGEN COM 09062X103 1,595,986 30,353 1.94 463,220 8.05 0.2640
2018-05-14 2018-03-31 13F BIOGEN COM 09062X103 1,565,633 37,247 2.44 428,701 -11.95 0.2526
2018-03-12 2017-12-31 13F/A-1 BIOGEN COM 09062X103 1,528,386 88,235 6.13 486,900 7.98 0.2998
2018-02-09 2017-12-31 13F BIOGEN COM 09062X103 1,528,386 88,235 486,900
2017-11-14 2017-09-30 13F BIOGEN COM 09062X103 1,440,151 -5,409 -0.37 450,931 14.96 0.2890
2017-08-17 2017-06-30 13F/A-1 BIOGEN COM 09062X103 1,445,560 1,414,707 4,585.31 392,265 4,549.34 0.2673
2017-08-14 2017-06-30 13F BIOGEN COM 09062X103 1,445,560 1,414,707 392,265
2017-05-03 2017-03-31 13F BIOGEN COM 09062X103 30,853 335 1.10 8,437 -2.58 0.0592
2017-01-30 2016-12-31 13F BIOGEN COM 09062X103 30,518 2,444 8.71 8,660 -1.46 0.0639
2016-10-24 2016-09-30 13F BIOGEN COM 09062X103 28,074 -1,911 -6.37 8,788 21.18 0.0648
2016-07-29 2016-06-30 13F BIOGEN COM 09062X103 29,985 -2,061 -6.43 7,252 -13.09 0.0603
2016-05-12 2016-03-31 13F BIOGEN COM 09062X103 32,046 0 0.00 8,344 -15.00 0.0677
2016-02-03 2015-12-31 13F BIOGEN COM 09062X103 32,046 0 0.00 9,816 5.10 0.0788
2015-11-16 2015-09-30 13F BIOGEN COM 09062X103 32,046 -51,484 -61.64 9,340 -72.32 0.0823
2015-08-17 2015-06-30 13F BIOGEN COM 09062X103 83,530 -28,320 -25.32 33,746 -28.57 0.2652
2015-06-02 2015-03-31 13F/A-1 BIOGEN COM 09062X103 111,850 12,396 12.46 47,246 39.84 0.3645
2015-05-15 2015-03-31 13F BIOGEN COM 09062X103 111,850 47,246
2015-02-12 2014-12-31 13F BIOGEN IDEC COM 09062X103 99,454 260 0.26 33,785 2.96 0.2436
2014-11-12 2014-09-30 13F BIOGEN IDEC COM 09062X103 99,194 -6,828 -6.44 32,815 -1.85 0.3087
2014-08-13 2014-06-30 13F BIOGEN IDEC COM 09062X103 106,022 -45,082 -29.84 33,434 -27.64 0.3122
2014-05-08 2014-03-31 13F BIOGEN IDEC COM 09062X103 151,104 3,715 2.52 46,203 12.09 0.4498
2014-01-14 2013-12-31 13F BIOGEN IDEC COM 09062X103 147,389 -14,477 -8.94 41,221 5.73 0.4165
2013-11-12 2013-09-30 13F BIOGEN IDEC COM 09062X103 161,866 -30,278 -15.76 38,988 -6.87 0.4301
2013-08-15 2013-06-30 13F BIOGEN IDEC COM 09062X103 192,144 192,144 41,863 0.4894
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.