Biogen Inc.
CL ˙ SNSE ˙ US09062X1037
SecurityCL:BIIB / Biogen Inc.
InstitutionSimplex Trading, Llc
Latest Disclosed Ownership2,164 shares
Latest Disclosed Value $ 396,726
Simplex Trading, Llc ownership in BIIB / Biogen Inc.

On May 14, 2026 - Simplex Trading, Llc filed a 13F-HR form disclosing ownership of 2,164 shares of Biogen Inc. (CL:BIIB) valued at $396,726 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 11, 2026 disclosing 30,878 shares of Biogen Inc.. This represents a change in shares of -92.99% during the quarter.

Simplex Trading, Llc has a history of taking positions in derivatives of the underlying security (BIIB) in the form of stock options. The firm currently holds call options representing 71,900 of underlying shares valued at $13,181,427 USD and put options representing 34,900 of underlying shares valued at $6,398,217 USD .

Note: prior versions of this page mistakenly stated that the share values represented the number of options, not the number of underlying shares. For more information on the data backing these reports, please see the SEC document Frequently Asked Questions About Form 13F.

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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Institutional Put/Call Ratios
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In addition to reporting standard equity and debt issues, institutions with more than 100MM assets under management must also disclose their put and call option holdings. Since put options generally indicate negative sentiment, and call options indicate positive sentiment, we can get a sense of the overall institutional sentiment by plotting the ratio of puts to calls. The chart to the right plots the historical put/call ratio for this instrument.

Using Put/Call Ratio as an indicator of investor sentiment overcomes one of the key deficiencies of using total institutional ownership, which is that a significant amount of assets under management are invested passively to track indices. Passively-managed funds do not typically buy options, so the put/call ratio indicator more closely tracks the sentiment of actively-managed funds.

CL:BIIB / Biogen Inc. Historical Put/Call Ratio
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 2,164 -28,714 -92.99 397 -92.71 0.0001
2026-02-11 2025-12-31 13F BIOGEN COM 09062X103 30,878 29,762 2,666.85 5,434 0.0031
2025-11-12 2025-09-30 13F BIOGEN COM 09062X103 1,116 -5,483 -83.09 0 0.0001
2025-08-05 2025-06-30 13F BIOGEN COM 09062X103 6,599 3,440 108.90 1 0.0005
2025-05-12 2025-03-31 13F BIOGEN COM 09062X103 3,159 -30,383 -90.58 0 -100.00 0.0003
2025-02-11 2024-12-31 13F BIOGEN COM 09062X103 33,542 -19,576 -36.85 5 -50.00 0.0029
2024-11-08 2024-09-30 13F BIOGEN COM 09062X103 53,118 32,405 156.45 10 150.00 0.0060
2024-07-25 2024-06-30 13F BIOGEN COM 09062X103 20,713 20,713 5 0.0030
2024-02-02 2023-12-31 13F BIOGEN COM 09062X103 0 -1,447 -100.00 0 0.0000
2023-11-01 2023-09-30 13F BIOGEN COM 09062X103 1,447 1,447 0 0.0003
2022-11-04 2022-09-30 13F BIOGEN COM 09062X103 0 -3,774 -100.00 0 -100.00
2022-08-03 2022-06-30 13F BIOGEN COM 09062X103 3,774 -5,576 -59.64 769 -60.94 0.0008
2022-05-02 2022-03-31 13F BIOGEN COM 09062X103 9,350 9,350 1,969 0.0018
2021-08-12 2021-06-30 13F BIOGEN COM 09062X103 0 -43,137 -100.00 0 0.0000
2021-04-26 2021-03-31 13F BIOGEN COM 09062X103 43,137 -2,766 -6.03 0 -100.00
2021-02-02 2020-12-31 13F BIOGEN COM 09062X103 45,903 45,903 6.41 11,239 0.0146
2020-02-05 2019-12-31 13F BIOGEN COM 09062X103 0 -68,075 -100.00 0 -100.00
2019-10-15 2019-09-30 13F BIOGEN COM 09062X103 68,075 68,075 15,849 0.0451
2018-10-23 2018-09-30 13F BIOGEN COM 09062X103 0 -1,620 -100.00 0 -100.00
2018-07-30 2018-06-30 13F BIOGEN COM 09062X103 1,620 1,620 470 0.0018
2018-04-26 2018-03-31 13F BIOGEN COM 09062X103 0 -13,807 -100.00 0 -100.00
2018-01-10 2017-12-31 13F BIOGEN COM 09062X103 13,807 5,928 75.24 4,398 78.27 0.1893
2017-10-25 2017-09-30 13F BIOGEN COM 09062X103 7,879 7,879 -42.93 2,467 -43.91 0.1007
2017-07-12 2017-06-30 13F BIOGEN COM 09062X103 0 -22,270 -100.00 0 -100.00
2017-04-21 2017-03-31 13F BIOGEN COM 09062X103 22,270 4,340 24.21 6,089 19.77 0.2635
2017-01-11 2016-12-31 13F BIOGEN COM 09062X103 17,930 -25,831 -59.03 5,084 -62.89 0.3037
2016-10-07 2016-09-30 13F BIOGEN COM 09062X103 43,761 -12,706 -22.50 13,698 0.32 0.9286
2016-07-18 2016-06-30 13F BIOGEN COM 09062X103 56,467 56,467 29.03 13,654 -0.32 0.9126
2016-01-20 2015-12-31 13F BIOGEN COM 09062X103 0 -16,253 -100.00 0 -100.00
2015-10-08 2015-09-30 13F BIOGEN COM 09062X103 16,253 -12,703 -43.87 4,742 -59.46 0.3476
2015-07-08 2015-06-30 13F BIOGEN COM 09062X103 28,956 22,130 324.20 11,696 305.83 0.9802
2015-04-21 2015-03-31 13F BIOGEN COM 09062X103 6,826 6,826 2,882 0.3352
Disclosed Call Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share
Price
Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2026-05-14 2026-03-31 13F BIOGEN CALL Call 71,900 22.91 13,181 28.03 n/a n/a n/a
2026-02-11 2025-12-31 13F BIOGEN CALL Call 58,500 -19.86 10,295 102,850.00 n/a n/a n/a
2025-11-12 2025-09-30 13F BIOGEN CALL Call 73,000 -8.86 10 0.00 n/a n/a n/a
2025-08-05 2025-06-30 13F BIOGEN CALL Call 80,100 -8.46 10 -9.09 n/a n/a n/a
2025-05-12 2025-03-31 13F BIOGEN CALL Call 87,500 25.54 12 10.00 n/a n/a n/a
2025-02-11 2024-12-31 13F BIOGEN CALL Call 69,700 31.02 11 0.00 n/a n/a n/a
2024-11-08 2024-09-30 13F BIOGEN CALL Call 53,200 -7.48 10 -23.08 n/a n/a n/a
2024-07-25 2024-06-30 13F BIOGEN CALL Call 57,500 -31.87 13 -27.78 n/a n/a n/a
2024-04-25 2024-03-31 13F BIOGEN CALL Call 84,400 -23.27 18 -35.71 n/a n/a n/a
2024-02-02 2023-12-31 13F BIOGEN CALL Call 110,000 4.27 28 3.70 n/a n/a n/a
2023-11-01 2023-09-30 13F BIOGEN CALL Call 105,500 34.22 27 22.73 n/a n/a n/a
2023-08-04 2023-06-30 13F BIOGEN CALL Call 78,600 -21.64 22 -18.52 n/a n/a n/a
2023-04-27 2023-03-31 13F BIOGEN CALL Call 100,300 -61.20 28 -61.97 n/a n/a n/a
2023-02-02 2022-12-31 13F BIOGEN CALL Call 258,500 -34.46 72 -99.93 n/a n/a n/a
2022-11-04 2022-09-30 13F BIOGEN CALL Call 394,400 66.41 105,304 117.87 n/a n/a n/a
2022-08-03 2022-06-30 13F BIOGEN CALL Call 237,000 9.27 48,333 5.81 n/a n/a n/a
2022-05-02 2022-03-31 13F BIOGEN CALL Call 216,900 0.23 45,679 -12.02 n/a n/a n/a
2022-02-23 2021-12-31 13F/A BIOGEN CALL Call 216,400 41.81 51,918 -2.49 n/a n/a n/a
2022-02-04 2021-12-31 13F BIOGEN CALL Call 152,600 53,245 n/a n/a n/a
2021-10-28 2021-09-30 13F BIOGEN CALL Call 152,600 3.46 53,245 4.25 n/a n/a n/a
2021-08-12 2021-06-30 13F BIOGEN CALL Call 147,500 5,990.01 51,074 n/a n/a n/a
2021-04-26 2021-03-31 13F BIOGEN CALL Call 2,422 -30.16 0 -100.00 n/a n/a n/a
2021-02-02 2020-12-31 13F BIOGEN CALL Call 3,468 90.34 84,917 64.29 n/a n/a n/a
2020-10-14 2020-09-30 13F BIOGEN CALL Call 1,822 9.04 51,686 15.61 n/a n/a n/a
2020-07-13 2020-06-30 13F BIOGEN CALL Call 1,671 3.98 44,707 -12.07 n/a n/a n/a
2020-04-29 2020-03-31 13F BIOGEN CALL Call 1,607 -22.18 50,842 -17.03 n/a n/a n/a
2020-02-05 2019-12-31 13F BIOGEN CALL Call 2,065 44.91 61,274 84.69 n/a n/a n/a
2019-10-15 2019-09-30 13F BIOGEN CALL Call 1,425 15.85 33,176 15.33 n/a n/a n/a
2019-07-26 2019-06-30 13F BIOGEN CALL Call 1,230 -19.24 28,766 -20.09 n/a n/a n/a
2019-04-18 2019-03-31 13F BIOGEN CALL Call 1,523 72.68 36,000 35.64 n/a n/a n/a
2019-01-16 2018-12-31 13F BIOGEN CALL Call 882 -1.78 26,540 -16.35 n/a n/a n/a
2018-10-23 2018-09-30 13F BIOGEN CALL Call 898 40.75 31,727 71.35 n/a n/a n/a
2018-07-30 2018-06-30 13F BIOGEN CALL Call 638 -8.99 18,516 2,930.44 n/a n/a n/a
2018-04-26 2018-03-31 13F BIOGEN CALL Call 701 -22.80 611 -63.61 n/a n/a n/a
2018-01-10 2017-12-31 13F BIOGEN CALL Call 908 -30.95 1,679 -11.96 n/a n/a n/a
2017-10-25 2017-09-30 13F BIOGEN CALL Call 1,315 -14.78 1,907 29.46 n/a n/a n/a
2017-07-12 2017-06-30 13F BIOGEN CALL Call 1,543 85.90 1,473 70.09 n/a n/a n/a
2017-04-21 2017-03-31 13F BIOGEN CALL Call 830 2.47 866 -17.37 n/a n/a n/a
2017-01-11 2016-12-31 13F BIOGEN CALL Call 810 1.38 1,048 -24.00 n/a n/a n/a
2016-10-07 2016-09-30 13F BIOGEN CALL Call 799 28.04 1,379 211.99 n/a n/a n/a
2016-07-18 2016-06-30 13F BIOGEN CALL Call 624 -36.59 442 -22.32 n/a n/a n/a
2016-04-14 2016-03-31 13F BIOGEN CALL Call 984 -59.95 569 -78.10 n/a n/a n/a
2016-01-20 2015-12-31 13F BIOGEN CALL Call 2,457 15.08 2,598 143.03 n/a n/a n/a
2015-10-08 2015-09-30 13F BIOGEN CALL Call 2,135 180.18 1,069 -66.05 n/a n/a n/a
2015-07-08 2015-06-30 13F BIOGEN CALL Call 762 18.69 3,149 2.64 n/a n/a n/a
2015-04-21 2015-03-31 13F BIOGEN CALL Call 642 -30.89 3,068 19.42 n/a n/a n/a
2015-03-04 2014-12-31 13F BIOGEN IDEC CALL Call 929 2,569 n/a n/a n/a
Disclosed Put Options
File
Date
Effective
Date
Form Security Class ID Opt Avg Share Price Shares ΔShares
(%)
Value
(x1000)
ΔValue
(%)
Prior Allocation
(%)
Allocation
(%)
ΔAllocation
(%)
Cost Basis
(x1000)
Profit
(x1000)
Return
(%)
2026-05-14 2026-03-31 13F BIOGEN PUT Put 34,900 -71.46 6,398 -70.27 n/a n/a n/a
2026-02-11 2025-12-31 13F BIOGEN PUT Put 122,300 314.58 21,524 537,975.00 n/a n/a n/a
2025-11-12 2025-09-30 13F BIOGEN PUT Put 29,500 -3.59 4 33.33 n/a n/a n/a
2025-08-05 2025-06-30 13F BIOGEN PUT Put 30,600 -71.61 4 -78.57 n/a n/a n/a
2025-05-12 2025-03-31 13F BIOGEN PUT Put 107,800 24.91 15 7.69 n/a n/a n/a
2025-02-11 2024-12-31 13F BIOGEN PUT Put 86,300 -24.96 13 -40.91 n/a n/a n/a
2024-11-08 2024-09-30 13F BIOGEN PUT Put 115,000 -4.25 22 -18.52 n/a n/a n/a
2024-07-25 2024-06-30 13F BIOGEN PUT Put 120,100 60.78 28 68.75 n/a n/a n/a
2024-04-25 2024-03-31 13F BIOGEN PUT Put 74,700 -33.00 16 -42.86 n/a n/a n/a
2024-02-02 2023-12-31 13F BIOGEN PUT Put 111,500 0.72 29 0.00 n/a n/a n/a
2023-11-01 2023-09-30 13F BIOGEN PUT Put 110,700 5.73 28 -3.45 n/a n/a n/a
2023-08-04 2023-06-30 13F BIOGEN PUT Put 104,700 -23.91 30 -23.68 n/a n/a n/a
2023-04-27 2023-03-31 13F BIOGEN PUT Put 137,600 -24.27 38 -24.00 n/a n/a n/a
2023-02-02 2022-12-31 13F BIOGEN PUT Put 181,700 -18.67 50 -99.92 n/a n/a n/a
2022-11-04 2022-09-30 13F BIOGEN PUT Put 223,400 61.88 59,647 111.94 n/a n/a n/a
2022-08-03 2022-06-30 13F BIOGEN PUT Put 138,000 17.05 28,143 13.35 n/a n/a n/a
2022-05-02 2022-03-31 13F BIOGEN PUT Put 117,900 25.16 24,829 9.86 n/a n/a n/a
2022-02-23 2021-12-31 13F/A BIOGEN PUT Put 94,200 -51.22 22,600 -66.46 n/a n/a n/a
2022-02-04 2021-12-31 13F BIOGEN PUT Put 193,100 67,376 n/a n/a n/a
2021-10-28 2021-09-30 13F BIOGEN PUT Put 193,100 1.90 67,376 2.68 n/a n/a n/a
2021-08-12 2021-06-30 13F BIOGEN PUT Put 189,500 17,896.20 65,618 n/a n/a n/a
2021-04-26 2021-03-31 13F BIOGEN PUT Put 1,053 -56.56 0 -100.00 n/a n/a n/a
2021-02-02 2020-12-31 13F BIOGEN PUT Put 2,424 46.29 59,354 26.27 n/a n/a n/a
2020-10-14 2020-09-30 13F BIOGEN PUT Put 1,657 -12.97 47,005 -7.73 n/a n/a n/a
2020-07-13 2020-06-30 13F BIOGEN PUT Put 1,904 17.39 50,941 -0.73 n/a n/a n/a
2020-04-29 2020-03-31 13F BIOGEN PUT Put 1,622 -9.13 51,316 -3.12 n/a n/a n/a
2020-02-05 2019-12-31 13F BIOGEN PUT Put 1,785 -36.20 52,966 -18.69 n/a n/a n/a
2019-10-15 2019-09-30 13F BIOGEN PUT Put 2,798 21.28 65,143 20.74 n/a n/a n/a
2019-07-26 2019-06-30 13F BIOGEN PUT Put 2,307 21.48 53,953 20.19 n/a n/a n/a
2019-04-18 2019-03-31 13F BIOGEN PUT Put 1,899 92.60 44,888 51.29 n/a n/a n/a
2019-01-16 2018-12-31 13F BIOGEN PUT Put 986 -28.65 29,670 -39.23 n/a n/a n/a
2018-10-23 2018-09-30 13F BIOGEN PUT Put 1,382 31.24 48,826 59.77 n/a n/a n/a
2018-07-30 2018-06-30 13F BIOGEN PUT Put 1,053 21.88 30,561 3,258.35 n/a n/a n/a
2018-04-26 2018-03-31 13F BIOGEN PUT Put 864 -46.86 910 13.61 n/a n/a n/a
2018-01-10 2017-12-31 13F BIOGEN PUT Put 1,626 29.05 801 -12.93 n/a n/a n/a
2017-10-25 2017-09-30 13F BIOGEN PUT Put 1,260 -23.03 920 -21.30 n/a n/a n/a
2017-07-12 2017-06-30 13F BIOGEN PUT Put 1,637 -7.83 1,169 -20.31 n/a n/a n/a
2017-04-21 2017-03-31 13F BIOGEN PUT Put 1,776 59.28 1,467 -2.91 n/a n/a n/a
2017-01-11 2016-12-31 13F BIOGEN PUT Put 1,115 0.36 1,511 81.61 n/a n/a n/a
2016-10-07 2016-09-30 13F BIOGEN PUT Put 1,111 -52.32 832 -67.28 n/a n/a n/a
2016-07-18 2016-06-30 13F BIOGEN PUT Put 2,330 143.47 2,543 -19.04 n/a n/a n/a
2016-04-14 2016-03-31 13F BIOGEN PUT Put 957 -29.06 3,141 15.48 n/a n/a n/a
2016-01-20 2015-12-31 13F BIOGEN PUT Put 1,349 -46.21 2,720 -55.73 n/a n/a n/a
2015-10-08 2015-09-30 13F BIOGEN PUT Put 2,508 105.74 6,144 214.75 n/a n/a n/a
2015-07-08 2015-06-30 13F BIOGEN PUT Put 1,219 9.92 1,952 129.38 n/a n/a n/a
2015-04-21 2015-03-31 13F BIOGEN PUT Put 1,109 -8.72 851 11.97 n/a n/a n/a
2015-03-04 2014-12-31 13F BIOGEN IDEC PUT Put 1,215 760 n/a n/a n/a
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.