Biogen Inc.
MX ˙ BMV ˙ US09062X1037
SecurityMX:BIIB / Biogen Inc.
InstitutionAmalgamated Bank
Latest Disclosed Ownership29,762 shares
Latest Disclosed Value $ 5,456
Amalgamated Bank reports 1.73% decrease in ownership of BIIB / Biogen Inc.

On May 8, 2026 - Amalgamated Bank filed a 13F-HR form disclosing ownership of 29,762 shares of Biogen Inc. (MX:BIIB) valued at $5,456 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 5, 2026 disclosing 30,285 shares of Biogen Inc.. This represents a change in shares of -1.73% 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)
2026-05-08 2026-03-31 13F BIOGEN COM 09062X103 29,762 -523 -1.73 5 0.00 0.0418
2026-02-05 2025-12-31 13F BIOGEN COM 09062X103 30,285 2,503 9.01 5 66.67 0.0385
2025-10-29 2025-09-30 13F BIOGEN COM 09062X103 27,782 -518 -1.83 4 0.00 0.0278
2025-08-04 2025-06-30 13F BIOGEN COM 09062X103 28,300 -154 -0.54 4 0.00 0.0274
2025-04-25 2025-03-31 13F BIOGEN COM 09062X103 28,454 253 0.90 4 -25.00 0.0333
2025-02-04 2024-12-31 13F BIOGEN COM 09062X103 28,201 -422 -1.47 4 -20.00 0.0354
2024-10-30 2024-09-30 13F BIOGEN COM 09062X103 28,623 -805 -2.74 6 -16.67 0.0457
2024-08-12 2024-06-30 13F BIOGEN COM 09062X103 29,428 -589 -1.96 7 0.00 0.0581
2024-04-23 2024-03-31 13F BIOGEN COM 09062X103 30,017 -4,839 -13.88 6 -33.33 0.0554
2024-02-06 2023-12-31 13F BIOGEN COM 09062X103 34,856 -2,897 -7.67 9 0.00 0.0720
2023-11-08 2023-09-30 13F BIOGEN COM 09062X103 37,753 993 2.70 10 -10.00 0.0826
2023-08-11 2023-06-30 13F BIOGEN COM 09062X103 36,760 -934 -2.48 10 0.00 0.0847
2023-05-02 2023-03-31 13F BIOGEN COM 09062X103 37,694 -81 -0.21 10 0.00 0.0893
2023-02-10 2022-12-31 13F BIOGEN COM 09062X103 37,775 547 1.47 10 -99.90 0.0933
2022-11-09 2022-09-30 13F BIOGEN COM 09062X103 37,228 406 1.10 9,940 32.37 0.0960
2022-08-15 2022-06-30 13F BIOGEN COM 09062X103 36,822 -43 -0.12 7,509 -3.28 0.0700
2022-08-25 2022-03-31 13F/A-1 BIOGEN COM 09062X103 36,865 -2,667 -6.75 7,764 -18.14 0.0603
2022-06-30 2022-03-31 13F BIOGEN COM 09062X103 36,865 -2,667 7,764 0.0617
2022-02-15 2021-12-31 13F/A-1 BIOGEN COM 09062X103 39,532 -771 -1.91 9,485 -16.83 0.0700
2022-02-15 2021-12-31 13F BIOGEN COM 09062X103 39,532 -771 9,485 0.0700
2021-10-29 2021-09-30 13F BIOGEN COM 09062X103 40,303 -2,182 -5.14 11,405 -22.47 0.0963
2021-08-16 2021-06-30 13F BIOGEN COM 09062X103 42,485 33,857 392.41 14,711 509.40 0.1179
2021-05-13 2021-03-31 13F BIOGEN COM 09062X103 8,628 -430 -4.75 2,414 8.84 0.0905
2021-02-12 2020-12-31 13F BIOGEN COM 09062X103 9,058 -291 -3.11 2,218 -16.37 0.0841
2020-10-30 2020-09-30 13F BIOGEN COM 09062X103 9,349 -525 -5.32 2,652 0.38 0.1153
2020-08-10 2020-06-30 13F BIOGEN COM 09062X103 9,874 -16,862 -63.07 2,642 -68.77 0.1223
2020-05-13 2020-03-31 13F BIOGEN COM 09062X103 26,736 -1,859 -6.50 8,459 -0.31 0.2068
2020-02-13 2019-12-31 13F BIOGEN COM 09062X103 28,595 -45 -0.16 8,485 27.25 0.1561
2019-11-13 2019-09-30 13F BIOGEN COM 09062X103 28,640 1,552 5.73 6,668 5.26 0.1402
2019-08-14 2019-06-30 13F BIOGEN COM 09062X103 27,088 -2,605 -8.77 6,335 -9.74 0.1479
2019-05-15 2019-03-31 13F BIOGEN COM 09062X103 29,693 308 1.05 7,019 -20.63 0.1701
2019-02-15 2018-12-31 13F BIOGEN COM 09062X103 29,385 -857 -2.83 8,843 -17.24 0.2506
2018-11-14 2018-09-30 13F BIOGEN COM 09062X103 30,242 -2,371 -7.27 10,685 12.88 0.2642
2018-07-18 2018-06-30 13F BIOGEN COM 09062X103 32,613 1,828 5.94 9,466 12.29 0.2313
2018-05-22 2018-03-31 13F BIOGEN COM 09062X103 30,785 2,838 10.15 8,430 -5.31 0.2236
2018-02-13 2017-12-31 13F BIOGEN IDEC COM 09062X103 27,947 2,452 9.62 8,903 11.52 0.2409
2017-11-09 2017-09-30 13F BIOGEN IDEC COM 09062X103 25,495 496 1.98 7,983 17.67 0.2486
2017-08-10 2017-06-30 13F BIOGEN IDEC COM 09062X103 24,999 8,426 50.84 6,784 49.72 0.2224
2017-05-12 2017-03-31 13F BIOGEN IDEC COM 09062X103 16,573 -7,128 -30.07 4,531 -32.58 0.2255
2017-02-14 2016-12-31 13F BIOGEN IDEC COM 09062X103 23,701 4,115 21.01 6,721 9.62 0.3038
2016-11-15 2016-09-30 13F/A-1 BIOGEN IDEC COM 09062X103 19,586 5 0.03 6,131 -0.44 0.3558
2016-11-14 2016-09-30 13F BIOGEN IDEC COM 09062X103 5,719 1,790
2016-08-16 2016-06-30 13F BIOGEN IDEC COM 09062X103 19,581 10,751 121.76 6,158 167.86 0.3563
2016-05-11 2016-03-31 13F BIOGEN IDEC COM 09062X103 8,830 2,082 30.85 2,299 11.22 0.2240
2016-02-10 2015-12-31 13F BIOGEN IDEC COM 09062X103 6,748 -2,183 -24.44 2,067 -20.68 0.2550
2015-11-04 2015-09-30 13F BIOGEN IDEC COM 09062X103 8,931 328 3.81 2,606 -25.01 0.2734
2015-07-10 2015-06-30 13F BIOGEN IDEC COM 09062X103 8,603 335 4.05 3,475 -0.46 0.3413
2015-04-22 2015-03-31 13F BIOGEN IDEC COM 09062X103 8,268 8,268 0.00 3,491 0.4262
2015-01-29 2014-12-31 13F BIOGEN IDEC COM 09062X103 0 -7,288 -100.00 0 -100.00
2014-11-14 2014-09-30 13F BIOGEN IDEC COM 09062X103 7,288 442 6.46 2,411 11.67 0.3588
2014-08-11 2014-06-30 13F BIOGEN IDEC COM 09062X103 6,846 788 13.01 2,159 16.51 0.3258
2014-05-12 2014-03-31 13F BIOGEN IDEC INC COM COM 09062X103 6,058 -121 -1.96 1,853 7.23 0.3193
2014-02-13 2013-12-31 13F BIOGEN IDEC INC COM COM 09062X103 6,179 6,179 -0.39 1,728 44.36 0.2937
2013-11-14 2013-09-30 13F BIOGEN IDEC INC COM COM 09062X103 0 0 0 0.0000
2013-08-15 2013-06-30 13F BIOGEN IDEC INC COM COM 09062X103 0 -6,203 -100.00 0 -100.00
2014-02-13 2013-03-31 13F BIOGEN IDEC INC COM COM 09062X103 6,203 2,066 49.94 1,197 97.20 0.3396
2014-02-11 2012-12-31 13F BIOGEN IDEC INC COM COM 09062X103 4,137 794 23.75 607 21.64 0.2528
2014-02-11 2012-09-30 13F BIOGEN IDEC INC COM COM 09062X103 3,343 105 3.24 499 6.62 0.3169
2014-02-11 2012-06-30 13F BIOGEN IDEC INC COM COM 09062X103 3,238 0 0.00 468 14.71 0.3360
2014-02-11 2012-03-31 13F BIOGEN IDEC INC COM COM 09062X103 3,238 -155 -4.57 408 9.38 0.2834
2014-02-11 2011-12-31 13F BIOGEN IDEC INC COM COM 09062X103 3,393 0 0.00 373 18.04 0.2681
2014-02-11 2011-09-30 13F BIOGEN IDEC INC COM COM 09062X103 3,393 227 7.17 316 -6.78 0.2589
2014-02-11 2011-06-30 13F BIOGEN IDEC INC COM COM 09062X103 3,166 -60 -1.86 339 43.04 0.2454
2014-02-11 2011-03-31 13F BIOGEN IDEC INC COM COM 09062X103 3,226 -157 -4.64 237 4.41 0.1722
2014-02-11 2010-12-31 13F BIOGEN IDEC INC COM COM 09062X103 3,383 3,383 227 0.1738
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.