Gossamer Bio, Inc.
DE ˙ DB ˙ US38341P1021
0,15 € ↓ -0,02 (-9,23%)
2026-06-04
DEL PRIS
SecurityDE:4GB / Gossamer Bio, Inc.
InstitutionGroup One Trading, L.p.
Latest Disclosed Ownership0 shares
Latest Disclosed Value $ 0
Group One Trading, L.p. ownership in 4GB / Gossamer Bio, Inc.

On February 11, 2026 - Group One Trading, L.p. filed a 13F-HR form disclosing ownership of 0 shares of Gossamer Bio, Inc. (DE:4GB) valued at $0 USD as of December 31, 2025. The entity filed a previous 13F-HR on November 12, 2025 disclosing 74,531 shares of Gossamer Bio, Inc.. This represents a change in shares of -100.00% during the quarter. The current value of the position is $0 USD.

Group One Trading, L.p. has a history of taking positions in derivatives of the underlying security (4GB) in the form of stock options. The firm currently holds call options representing 1,456,200 of underlying shares valued at $4,514,220 USD and put options representing 11,900 of underlying shares valued at $36,890 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.

DE:4GB / Gossamer Bio, 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)
2026-02-11 2025-12-31 13F GOSSAMER BIO COM 38341P102 0 -74,531 -100.00 0 -100.00
2025-11-12 2025-09-30 13F GOSSAMER BIO COM 38341P102 74,531 -158,639 -68.04 196 -31.47 0.0003
2025-08-14 2025-06-30 13F GOSSAMER BIO COM 38341P102 233,170 25,426 12.24 287 25.44 0.0006
2025-05-14 2025-03-31 13F GOSSAMER BIO COM 38341P102 207,744 133,100 178.31 229 240.30 0.0007
2025-05-14 2024-12-31 13F/A-1 GOSSAMER BIO COM 38341P102 74,644 63,580 574.66 68 570.00 0.0002
2025-02-14 2024-12-31 13F GOSSAMER BIO COM 38341P102 74,644 63,580 68 0.0002
2024-11-14 2024-09-30 13F GOSSAMER BIO COM 38341P102 11,064 11,064 11 0.0000
2023-05-12 2023-03-31 13F GOSSAMER BIO COM 38341P102 0 -58,938 -100.00 0 -100.00
2023-02-09 2022-12-31 13F GOSSAMER BIO COM 38341P102 58,938 -72,281 -55.08 128 -91.92 0.0003
2022-11-09 2022-09-30 13F GOSSAMER BIO COM 38341P102 131,219 -2,985 -2.22 1,572 39.98 0.0031
2022-08-11 2022-06-30 13F GOSSAMER BIO COM 38341P102 134,204 126,664 1,679.89 1,123 1,627.69 0.0018
2022-05-12 2022-03-31 13F GOSSAMER BIO COM 38341P102 7,540 -4,259 -36.10 65 -51.13 0.0001
2022-02-11 2021-12-31 13F GOSSAMER BIO COM 38341P102 11,799 -2,211 -15.78 133 -24.43 0.0001
2021-11-12 2021-09-30 13F GOSSAMER BIO COM 38341P102 14,010 13,910 13,910.00 176 17,500.00 0.0002
2021-08-10 2021-06-30 13F GOSSAMER BIO COM 38341P102 100 100 1 0.0000
2021-05-12 2021-03-31 13F GOSSAMER BIO COM 38341P102 0 -5,088 -100.00 0 -100.00
2021-02-10 2020-12-31 13F GOSSAMER BIO COM 38341P102 5,088 4,900 2,606.38 49 2,350.00 0.0001
2020-11-12 2020-09-30 13F GOSSAMER BIO COM 38341P102 188 -1,000 -84.18 2 -86.67 0.0000
2020-08-13 2020-06-30 13F GOSSAMER BIO COM 38341P102 1,188 -60,207 -98.06 15 -97.59 0.0001
2020-05-13 2020-03-31 13F GOSSAMER BIO COM 38341P102 61,395 61,395 623 0.0051
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
(%)
2026-02-11 2025-12-31 13F GOSSAMER BIO COM Call 1,456,200 104.29 4,514 140.88 n/a n/a n/a
2025-11-12 2025-09-30 13F GOSSAMER BIO COM Call 712,800 647.17 1,875 1,501.71 n/a n/a n/a
2025-08-14 2025-06-30 13F GOSSAMER BIO COM Call 95,400 19.40 117 34.48 n/a n/a n/a
2025-05-14 2025-03-31 13F GOSSAMER BIO COM Call 79,900 -13.53 88 4.82 n/a n/a n/a
2025-05-14 2024-12-31 13F/A GOSSAMER BIO COM Call 92,400 24.19 84 13.70 n/a n/a n/a
2025-02-14 2024-12-31 13F GOSSAMER BIO COM Call 92,400 84 n/a n/a n/a
2024-11-14 2024-09-30 13F GOSSAMER BIO COM Call 74,400 76.30 73 92.11 n/a n/a n/a
2024-08-14 2024-06-30 13F GOSSAMER BIO COM Call 42,200 9.61 38 -15.56 n/a n/a n/a
2024-05-10 2024-03-31 13F GOSSAMER BIO COM Call 38,500 -98.61 45 -98.23 n/a n/a n/a
2024-02-14 2023-12-31 13F GOSSAMER BIO COM Call 2,779,400 -3.28 2,536 5.98 n/a n/a n/a
2023-11-09 2023-09-30 13F GOSSAMER BIO COM Call 2,873,600 307.78 2,393 183.20 n/a n/a n/a
2023-08-09 2023-06-30 13F GOSSAMER BIO COM Call 704,700 -32.71 846 -35.94 n/a n/a n/a
2023-05-12 2023-03-31 13F GOSSAMER BIO COM Call 1,047,200 2,715.05 1,319 1,548.75 n/a n/a n/a
2023-02-09 2022-12-31 13F GOSSAMER BIO COM Call 37,200 -35.42 81 -88.41 n/a n/a n/a
2022-11-09 2022-09-30 13F GOSSAMER BIO COM Call 57,600 -1.03 690 41.68 n/a n/a n/a
2022-08-11 2022-06-30 13F GOSSAMER BIO COM Call 58,200 160.99 487 151.03 n/a n/a n/a
2022-05-12 2022-03-31 13F GOSSAMER BIO COM Call 22,300 7,333.33 194 6,366.67 n/a n/a n/a
2022-02-11 2021-12-31 13F GOSSAMER BIO COM Call 300 -96.63 3 -97.32 n/a n/a n/a
2021-11-12 2021-09-30 13F GOSSAMER BIO COM Call 8,900 41.27 112 119.61 n/a n/a n/a
2021-08-10 2021-06-30 13F GOSSAMER BIO COM Call 6,300 18.87 51 4.08 n/a n/a n/a
2021-05-12 2021-03-31 13F GOSSAMER BIO COM Call 5,300 1,666.67 49 1,533.33 n/a n/a n/a
2021-02-10 2020-12-31 13F GOSSAMER BIO COM Call 300 0.00 3 -25.00 n/a n/a n/a
2020-11-12 2020-09-30 13F GOSSAMER BIO COM Call 300 -90.62 4 -90.48 n/a n/a n/a
2020-08-13 2020-06-30 13F GOSSAMER BIO COM Call 3,200 28.00 42 68.00 n/a n/a n/a
2020-05-13 2020-03-31 13F GOSSAMER BIO COM Call 2,500 -74.23 25 -83.55 n/a n/a n/a
2020-02-10 2019-12-31 13F GOSSAMER BIO COM Call 9,700 169.44 152 153.33 n/a n/a n/a
2019-11-12 2019-09-30 13F GOSSAMER BIO COM Call 3,600 60 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
(%)
2026-02-11 2025-12-31 13F GOSSAMER BIO COM Put 11,900 -41.67 37 -32.08 n/a n/a n/a
2025-11-12 2025-09-30 13F GOSSAMER BIO COM Put 20,400 50.00 54 231.25 n/a n/a n/a
2025-08-14 2025-06-30 13F GOSSAMER BIO COM Put 13,600 7.94 17 23.08 n/a n/a n/a
2025-05-14 2025-03-31 13F GOSSAMER BIO COM Put 12,600 21.15 14 44.44 n/a n/a n/a
2025-05-14 2024-12-31 13F/A GOSSAMER BIO COM Put 10,400 316.00 9 350.00 n/a n/a n/a
2025-02-14 2024-12-31 13F GOSSAMER BIO COM Put 10,400 9 n/a n/a n/a
2024-11-14 2024-09-30 13F GOSSAMER BIO COM Put 2,500 -85.96 2 -87.50 n/a n/a n/a
2024-08-14 2024-06-30 13F GOSSAMER BIO COM Put 17,800 323.81 16 300.00 n/a n/a n/a
2024-05-10 2024-03-31 13F GOSSAMER BIO COM Put 4,200 -97.55 5 -97.44 n/a n/a n/a
2024-02-14 2023-12-31 13F GOSSAMER BIO COM Put 171,600 0.94 157 10.64 n/a n/a n/a
2023-11-09 2023-09-30 13F GOSSAMER BIO COM Put 170,000 8,400.00 142 6,950.00 n/a n/a n/a
2023-08-09 2023-06-30 13F GOSSAMER BIO COM Put 2,000 -65.52 2 -71.43 n/a n/a n/a
2023-05-12 2023-03-31 13F GOSSAMER BIO COM Put 5,800 -92.23 7 -95.65 n/a n/a n/a
2023-02-09 2022-12-31 13F GOSSAMER BIO COM Put 74,600 496.80 162 7.33 n/a n/a n/a
2022-11-09 2022-09-30 13F GOSSAMER BIO COM Put 12,500 150 n/a n/a n/a
2022-02-11 2021-12-31 13F GOSSAMER BIO COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2021-11-12 2021-09-30 13F GOSSAMER BIO COM Put 300 -97.00 4 -95.06 n/a n/a n/a
2021-08-10 2021-06-30 13F GOSSAMER BIO COM Put 10,000 81 n/a n/a n/a
2021-05-12 2021-03-31 13F GOSSAMER BIO COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2021-02-10 2020-12-31 13F GOSSAMER BIO COM Put 12,100 117 n/a n/a n/a
2020-11-12 2020-09-30 13F GOSSAMER BIO COM Put 0 -100.00 0 -100.00 n/a n/a n/a
2020-08-13 2020-06-30 13F GOSSAMER BIO COM Put 400 -99.65 5 -99.57 n/a n/a n/a
2020-05-13 2020-03-31 13F GOSSAMER BIO COM Put 115,300 1,437.33 1,170 900.00 n/a n/a n/a
2020-02-10 2019-12-31 13F GOSSAMER BIO COM Put 7,500 -90.52 117 -91.19 n/a n/a n/a
2019-11-12 2019-09-30 13F GOSSAMER BIO COM Put 79,100 1,328 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.