Biogen Inc.
MX ˙ BMV ˙ US09062X1037
SecurityMX:BIIB / Biogen Inc.
InstitutionKinneret Advisory, LLC
Latest Disclosed Ownership17,946 shares
Latest Disclosed Value $ 3,290,040
Kinneret Advisory, LLC reports 4.25% decrease in ownership of BIIB / Biogen Inc.

On May 14, 2026 - Kinneret Advisory, LLC filed a 13F-HR form disclosing ownership of 17,946 shares of Biogen Inc. (MX:BIIB) valued at $3,290,040 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 12, 2026 disclosing 18,742 shares of Biogen Inc.. This represents a change in shares of -4.25% 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)
2026-05-14 2026-03-31 13F BIOGEN COM 09062X103 17,946 -796 -4.25 3,290 -0.24 0.3118
2026-02-12 2025-12-31 13F BIOGEN COM 09062X103 18,742 -512 -2.66 3,298 22.28 0.2793
2025-11-05 2025-09-30 13F BIOGEN COM 09062X103 19,254 -86 -0.44 2,697 11.08 0.2295
2025-07-25 2025-06-30 13F BIOGEN COM 09062X103 19,340 -29 -0.15 2,429 -8.38 0.2212
2025-07-21 2025-03-31 13F/A-1 BIOGEN COM 09062X103 19,369 -66 -0.34 2,650 -10.83 0.2671
2025-04-29 2025-03-31 13F BIOGEN COM 09062X103 13,038 -6,397 1,784 0.2671
2025-02-03 2024-12-31 13F BIOGEN COM 09062X103 19,435 -905 -4.45 2,972 -24.61 0.2806
2024-11-04 2024-09-30 13F BIOGEN COM 09062X103 20,340 -266 -1.29 3,943 -17.46 0.3618
2024-07-26 2024-06-30 13F BIOGEN COM 09062X103 20,606 7,885 61.98 4,777 74.12 0.4582
2024-04-25 2024-03-31 13F BIOGEN COM 09062X103 12,721 -40 -0.31 2,743 -16.93 0.2742
2024-02-14 2023-12-31 13F BIOGEN COM 09062X103 12,761 -81 -0.63 3,302 0.06 0.3656
2023-10-12 2023-09-30 13F BIOGEN COM 09062X903 12,842 -8 -0.06 3,301 -9.84 0.4077
2023-08-02 2023-06-30 13F BIOGEN COM 09062X103 12,850 0 0.00 3,660 2.46 0.4336
2023-04-27 2023-03-31 13F BIOGEN COM 09062X103 12,850 -690 -5.10 3,573 -4.72 0.4614
2023-02-14 2022-12-31 13F BIOGEN COM 09062X103 13,540 5,262 63.57 3,749 69.64 0.4956
2022-11-02 2022-09-30 13F BIOGEN COM 09062X103 8,278 0 0.00 2,210 30.92 0.3066
2022-08-04 2022-06-30 13F BIOGEN COM 09062X103 8,278 175 2.16 1,688 -1.06 0.2190
2022-05-13 2022-03-31 13F BIOGEN COM 09062X103 8,103 182 2.30 1,706 -10.21 0.1873
2022-02-08 2021-12-31 13F BIOGEN COM 09062X103 7,921 0 0.00 1,900 -15.25 0.1967
2021-11-09 2021-09-30 13F BIOGEN COM 09062X103 7,921 0 0.00 2,242 -18.26 0.2628
2021-08-16 2021-06-30 13F BIOGEN COM 09062X103 7,921 0 0.00 2,743 23.78 0.3241
2021-05-13 2021-03-31 13F BIOGEN COM 09062X103 7,921 0 0.00 2,216 14.23 0.2845
2021-02-11 2020-12-31 13F BIOGEN COM 09062X103 7,921 0 0.00 1,940 -13.66 0.2633
2020-11-13 2020-09-30 13F BIOGEN COM 09062X103 7,921 -255 -3.12 2,247 2.74 0.3406
2020-08-12 2020-06-30 13F BIOGEN COM 09062X103 8,176 0 0.00 2,187 -15.46 0.3517
2020-05-14 2020-03-31 13F BIOGEN COM 09062X103 8,176 916 12.62 2,587 20.10 0.5039
2020-02-10 2019-12-31 13F BIOGEN COM 09062X103 7,260 0 0.00 2,154 27.46 0.3917
2019-11-13 2019-09-30 13F BIOGEN COM 09062X103 7,260 0 0.00 1,690 -0.47 0.3365
2019-08-13 2019-06-30 13F BIOGEN COM 09062X103 7,260 0 0.00 1,698 -1.05 0.3442
2019-05-15 2019-03-31 13F BIOGEN COM 09062X103 7,260 -463 -6.00 1,716 -26.16 0.3611
2019-02-13 2018-12-31 13F BIOGEN COM 09062X103 7,723 7,723 2,324 0.6881
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.