Biogen Inc.
US ˙ NasdaqGS ˙ US09062X1037

SecurityBIIB / Biogen Inc.
InstitutionNeuberger Berman Group LLC
Latest Disclosed Ownership11,651 shares
Latest Disclosed Value $ 2,135,988
Neuberger Berman Group LLC reports 2.17% increase in ownership of BIIB / Biogen Inc.

On May 14, 2026 - Neuberger Berman Group LLC filed a 13F-HR form disclosing ownership of 11,651 shares of Biogen Inc. (US:BIIB) valued at $2,135,978 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 11,404 shares of Biogen Inc.. This represents a change in shares of 2.17% during the quarter. The current value of the position is $2,275,906 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)
2026-05-14 2026-03-31 13F BIOGEN Common 09062X103 11,651 247 2.17 2,136 6.38 0.0008
2026-02-13 2025-12-31 13F BIOGEN Common 09062X103 11,404 426 3.88 2,007 30.58 0.0015
2025-11-12 2025-09-30 13F BIOGEN Common 09062X103 10,978 -138 -1.24 1,538 10.10 0.0011
2025-08-25 2025-06-30 13F/A-1 BIOGEN Common 09062X103 11,116 4,226 61.34 1,396 48.20 0.0011
2025-08-13 2025-06-30 13F BIOGEN Common 09062X103 11,116 4,226 1,396 0.0006
2025-05-13 2025-03-31 13F BIOGEN Common 09062X103 6,890 3,448 100.17 943 79.09 0.0008
2025-02-13 2024-12-31 13F BIOGEN Common 09062X103 3,442 -28,657 -89.28 526 -91.55 0.0004
2024-11-14 2024-09-30 13F BIOGEN Common 09062X103 32,099 593 1.88 6,222 -14.80 0.0049
2024-11-14 2024-06-30 13F/A-1 BIOGEN Common 09062X103 31,506 11,810 59.96 7,304 71.96 0.0060
2024-08-13 2024-06-30 13F BIOGEN Common 09062X103 31,506 11,810 7,304 0.0060
2024-11-14 2024-03-31 13F/A-1 BIOGEN Common 09062X103 19,696 -2,697 -12.04 4,247 -26.70 0.0035
2024-05-13 2024-03-31 13F BIOGEN Common 09062X103 19,696 -2,697 4,247 0.0035
2024-11-14 2023-12-31 13F/A-2 BIOGEN Common 09062X103 22,393 2,266 11.26 5,795 12.03 0.0051
2024-02-09 2023-12-31 13F BIOGEN Common 09062X103 22,393 2,266 5,795 0.0051
2023-11-14 2023-09-30 13F BIOGEN Common 09062X103 20,127 -292,312 -93.56 5,173 -94.19 0.0047
2023-08-11 2023-06-30 13F BIOGEN Common 09062X103 312,439 -25 -0.01 88,998 2.44 0.0796
2023-05-12 2023-03-31 13F BIOGEN Common 09062X103 312,464 10,933 3.63 86,874 4.04 0.0806
2023-02-13 2022-12-31 13F BIOGEN Common 09062X103 301,531 -103,962 -25.64 83,500 -22.88 0.0819
2022-11-15 2022-09-30 13F BIOGEN Common 09062X103 405,493 193,812 91.56 108,268 150.78 0.1130
2022-08-15 2022-06-30 13F BIOGEN Common 09062X103 211,681 200,289 1,758.15 43,172 1,699.58 0.0434
2022-05-23 2022-03-31 13F/A-1 BIOGEN Common 09062X103 11,392 490 4.49 2,399 16.63 0.0020
2022-05-13 2022-03-31 13F BIOGEN Common 09062X103 11,392 490 1,976 0.0009
2022-02-11 2021-12-31 13F BIOGEN Common 09062X103 10,902 3,008 38.10 2,057 33.14 0.0016
2021-11-12 2021-09-30 13F BIOGEN Common 09062X103 7,894 -16 -0.20 1,545 -22.01 0.0014
2021-08-13 2021-06-30 13F BIOGEN Common 09062X103 7,910 2,577 48.32 1,981 40.30 0.0017
2021-05-13 2021-03-31 13F BIOGEN Common 09062X103 5,333 468 9.62 1,412 21.41 0.0013
2021-02-10 2020-12-31 13F BIOGEN Common 09062X103 4,865 -2,106 -30.21 1,163 -39.90 0.0012
2020-11-12 2020-09-30 13F BIOGEN Common 09062X103 6,971 -2,649 -27.54 1,935 -24.15 0.0023
2020-08-13 2020-06-30 13F BIOGEN Common 09062X103 9,620 3,146 48.59 2,551 24.56 0.0032
2020-05-14 2020-03-31 13F BIOGEN Common 09062X103 6,474 272 4.39 2,048 11.30 0.0031
2020-02-12 2019-12-31 13F BIOGEN Common 09062X103 6,202 -409 -6.19 1,840 19.56 0.0021
2019-11-13 2019-09-30 13F BIOGEN Common 09062X103 6,611 -1,733 -20.77 1,539 -21.12 0.0019
2019-08-13 2019-06-30 13F BIOGEN Common 09062X103 8,344 -10,347 -55.36 1,951 -55.84 0.0023
2019-05-13 2019-03-31 13F BIOGEN Common 09062X103 18,691 112 0.60 4,418 -20.97 0.0054
2019-02-12 2018-12-31 13F BIOGEN Common 09062X103 18,579 -2,456 -11.68 5,590 -24.77 0.0078
2018-11-16 2018-09-30 13F/A-1 BIOGEN Common 09062X103 21,035 583 2.85 7,431 25.08 0.0084
2018-11-13 2018-09-30 13F BIOGEN Common 09062X103 21,035 583 7,431
2018-08-13 2018-06-30 13F BIOGEN Common 09062X103 20,452 -804 -3.78 5,941 2.01 0.0066
2018-05-08 2018-03-31 13F BIOGEN Common 09062X103 21,256 427 2.05 5,824 -12.33 0.0067
2018-02-14 2017-12-31 13F BIOGEN Common 09062X103 20,829 -5,815 -21.82 6,643 -20.38 0.0076
2017-11-15 2017-09-30 13F BIOGEN IDEC COMMON STOCK 09062X103 26,644 -1,330 -4.75 8,343 9.91 0.0104
2017-08-08 2017-06-30 13F BIOGEN IDEC COMMON STOCK 09062X103 27,974 4,389 18.61 7,591 17.71 0.0097
2017-05-10 2017-03-31 13F BIOGEN IDEC COMMON STOCK 09062X103 23,585 1,560 7.08 6,449 3.25 0.0083
2017-02-06 2016-12-31 13F BIOGEN IDEC COMMON STOCK 09062X103 22,025 4,390 24.89 6,246 13.15 0.0084
2016-11-02 2016-09-30 13F BIOGEN IDEC COMMON STOCK 09062X103 17,635 3,750 27.01 5,520 64.38 0.0075
2016-08-05 2016-06-30 13F BIOGEN IDEC COMMON STOCK 09062X103 13,885 3,620 35.27 3,358 25.67 0.0046
2016-05-06 2016-03-31 13F BIOGEN IDEC COMMON STOCK 09062X103 10,265 -74 -0.72 2,672 -15.63 0.0037
2016-01-28 2015-12-31 13F BIOGEN IDEC COMMON STOCK 09062X103 10,339 -4,212 -28.95 3,167 -25.41 0.0041
2015-11-10 2015-09-30 13F BIOGEN IDEC COMMON STOCK 09062X103 14,551 -216,067 -93.69 4,246 -95.44 0.0055
2015-07-31 2015-06-30 13F BIOGEN IDEC COMMON STOCK 09062X103 230,618 148,386 180.45 93,156 168.29 0.1036
2015-05-06 2015-03-31 13F BIOGEN IDEC COMMON STOCK 09062X103 82,232 82,232 0.00 34,722 0.0371
2015-02-05 2014-12-31 13F BIOGEN IDEC COMMON STOCK 09062X103 0 -8,594 -100.00 0 -100.00
2014-11-04 2014-09-30 13F BIOGEN IDEC COMMON STOCK 09062X103 8,594 -480 -5.29 2,842 -0.66 0.0029
2014-08-05 2014-06-30 13F BIOGEN IDEC COMMON STOCK 09062X103 9,074 -2,226 -19.70 2,861 -17.22 0.0028
2014-05-05 2014-03-31 13F BIOGEN IDEC COMMON STOCK 09062X103 11,300 -264,796 -95.91 3,456 -95.52 0.0035
2014-02-11 2013-12-31 13F BIOGEN IDEC COMMON STOCK 09062X103 276,096 -17,225 -5.87 77,189 9.30 0.0793
2013-10-29 2013-09-30 13F/A-1 BIOGEN IDEC COMMON STOCK 09062X103 293,321 -197,221 -40.20 70,620 -33.10 0.0784
2013-10-29 2013-09-30 13F BIOGEN IDEC COMMON STOCK 09062X103 1,363,572 171,810
2013-08-13 2013-06-30 13F BIOGEN IDEC COMMON STOCK 09062X103 490,542 490,542 105,565 0.1255
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.