Gossamer Bio, Inc.
US ˙ NasdaqGS ˙ US38341P1021

SecurityGOSS / Gossamer Bio, Inc.
InstitutionSimplex Trading, Llc
Latest Disclosed Ownership0 shares
Latest Disclosed Value $ 0
Simplex Trading, Llc ownership in GOSS / Gossamer Bio, Inc.

On April 25, 2024 - Simplex Trading, Llc filed a 13F-HR form disclosing ownership of 0 shares of Gossamer Bio, Inc. (US:GOSS) valued at $0 USD as of March 31, 2024. The entity filed a previous 13F-HR on February 2, 2024 disclosing 10,505 shares of Gossamer Bio, Inc.. The current value of the position is $0 USD.

Simplex Trading, Llc has a history of taking positions in derivatives of the underlying security (GOSS) in the form of stock options. The firm currently holds call options representing 735,300 of underlying shares valued at $241,546 USD and put options representing 13,400 of underlying shares valued at $4,401 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.

GOSS / 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)
2024-04-25 2024-03-31 13F GOSSAMER BIO COM 38341P102 0 -10,505 -100.00 0 0.0000
2024-02-02 2023-12-31 13F GOSSAMER BIO COM 38341P102 10,505 10,505 0 0.0000
2023-08-04 2023-06-30 13F GOSSAMER BIO COM 38341P102 0 -100 -100.00 0 0.0000
2023-04-27 2023-03-31 13F GOSSAMER BIO COM 38341P102 100 -60,245 -99.83 0 0.0000
2023-02-02 2022-12-31 13F GOSSAMER BIO COM 38341P102 60,345 39,557 190.29 0 -100.00 0.0001
2022-11-04 2022-09-30 13F GOSSAMER BIO COM 38341P102 20,788 550 2.72 249 47.34 0.0003
2022-08-03 2022-06-30 13F GOSSAMER BIO COM 38341P102 20,238 17,328 595.46 169 576.00 0.0002
2022-05-02 2022-03-31 13F GOSSAMER BIO COM 38341P102 2,910 -13,119 -81.85 25 -86.19 0.0000
2022-02-23 2021-12-31 13F/A-1 GOSSAMER BIO COM 38341P102 16,029 16,029 181 0.0002
2021-08-12 2021-06-30 13F GOSSAMER BIO COM 38341P102 0 -5,267 -100.00 0 -100.00
2021-04-26 2021-03-31 13F GOSSAMER BIO COM 38341P102 5,267 -11,639 -68.85 48 -70.55 0.0001
2021-02-02 2020-12-31 13F GOSSAMER BIO COM 38341P102 16,906 5,017 42.20 163 10.88 0.0002
2020-10-14 2020-09-30 13F GOSSAMER BIO COM 38341P102 11,889 7,635 179.48 147 167.27 0.0002
2020-07-13 2020-06-30 13F GOSSAMER BIO COM 38341P102 4,254 -38,601 -90.07 55 -87.33 0.0001
2020-04-29 2020-03-31 13F GOSSAMER BIO COM 38341P102 42,855 42,855 907.40 434 689.09 0.0008
2020-02-05 2019-12-31 13F GOSSAMER BIO COM 38341P102 0 -3,321 -100.00 0 -100.00
2019-10-15 2019-09-30 13F GOSSAMER BIO COM 38341P102 3,321 3,321 55 0.0002
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 GOSSAMER BIO CALL Call 735,300 -53.77 242 -95.11 n/a n/a n/a
2026-02-11 2025-12-31 13F GOSSAMER BIO CALL Call 1,590,600 22.13 4,931 164,233.33 n/a n/a n/a
2025-11-12 2025-09-30 13F GOSSAMER BIO CALL Call 1,302,400 145.00 3 n/a n/a n/a
2025-08-05 2025-06-30 13F GOSSAMER BIO CALL Call 531,600 48.24 1 n/a n/a n/a
2025-05-12 2025-03-31 13F GOSSAMER BIO CALL Call 358,600 24.47 0 n/a n/a n/a
2025-02-11 2024-12-31 13F GOSSAMER BIO CALL Call 288,100 -1.44 0 n/a n/a n/a
2024-11-08 2024-09-30 13F GOSSAMER BIO CALL Call 292,300 81.55 0 n/a n/a n/a
2024-07-25 2024-06-30 13F GOSSAMER BIO CALL Call 161,000 34.84 0 n/a n/a n/a
2024-04-25 2024-03-31 13F GOSSAMER BIO CALL Call 119,400 -55.73 0 n/a n/a n/a
2024-02-02 2023-12-31 13F GOSSAMER BIO CALL Call 269,700 -20.61 0 n/a n/a n/a
2023-11-01 2023-09-30 13F GOSSAMER BIO CALL Call 339,700 180.51 0 n/a n/a n/a
2023-08-04 2023-06-30 13F GOSSAMER BIO CALL Call 121,100 -65.17 0 n/a n/a n/a
2023-04-27 2023-03-31 13F GOSSAMER BIO CALL Call 347,700 953.64 0 n/a n/a n/a
2023-02-02 2022-12-31 13F GOSSAMER BIO CALL Call 33,000 340.00 0 -100.00 n/a n/a n/a
2022-11-04 2022-09-30 13F GOSSAMER BIO CALL Call 7,500 -2.60 89 39.06 n/a n/a n/a
2022-08-03 2022-06-30 13F GOSSAMER BIO CALL Call 7,700 57.14 64 52.38 n/a n/a n/a
2022-05-02 2022-03-31 13F GOSSAMER BIO CALL Call 4,900 11.36 42 -14.29 n/a n/a n/a
2022-02-23 2021-12-31 13F/A GOSSAMER BIO CALL Call 4,400 528.57 49 880.00 n/a n/a n/a
2022-02-04 2021-12-31 13F GOSSAMER BIO CALL Call 700 5 n/a n/a n/a
2021-10-28 2021-09-30 13F GOSSAMER BIO CALL Call 700 0.00 5 0.00 n/a n/a n/a
2021-08-12 2021-06-30 13F GOSSAMER BIO CALL Call 700 3,788.89 5 -68.75 n/a n/a n/a
2021-04-26 2021-03-31 13F GOSSAMER BIO CALL Call 18 -10.00 16 -15.79 n/a n/a n/a
2021-02-02 2020-12-31 13F GOSSAMER BIO CALL Call 20 11.11 19 18.75 n/a n/a n/a
2020-10-14 2020-09-30 13F GOSSAMER BIO CALL Call 0 -100.00 0 -100.00 n/a n/a n/a
2020-07-13 2020-06-30 13F GOSSAMER BIO CALL Call 138 430.77 179 588.46 n/a n/a n/a
2020-04-29 2020-03-31 13F GOSSAMER BIO CALL Call 26 -87.25 26 -91.82 n/a n/a n/a
2020-02-05 2019-12-31 13F GOSSAMER BIO CALL Call 204 -28.92 318 -33.89 n/a n/a n/a
2019-10-15 2019-09-30 13F GOSSAMER BIO CALL Call 287 481 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 GOSSAMER BIO PUT Put 13,400 -64.46 4 -96.55 n/a n/a n/a
2026-02-11 2025-12-31 13F GOSSAMER BIO PUT Put 37,700 -20.13 117 n/a n/a n/a
2025-11-12 2025-09-30 13F GOSSAMER BIO PUT Put 47,200 28.96 0 n/a n/a n/a
2025-08-05 2025-06-30 13F GOSSAMER BIO PUT Put 36,600 0.27 0 n/a n/a n/a
2025-05-12 2025-03-31 13F GOSSAMER BIO PUT Put 36,500 -62.25 0 n/a n/a n/a
2025-02-11 2024-12-31 13F GOSSAMER BIO PUT Put 96,700 51.33 0 n/a n/a n/a
2024-11-08 2024-09-30 13F GOSSAMER BIO PUT Put 63,900 -19.92 0 n/a n/a n/a
2024-07-25 2024-06-30 13F GOSSAMER BIO PUT Put 79,800 38.78 0 n/a n/a n/a
2024-04-25 2024-03-31 13F GOSSAMER BIO PUT Put 57,500 -72.40 0 n/a n/a n/a
2024-02-02 2023-12-31 13F GOSSAMER BIO PUT Put 208,300 -0.95 0 n/a n/a n/a
2023-11-01 2023-09-30 13F GOSSAMER BIO PUT Put 210,300 6,471.88 0 n/a n/a n/a
2023-08-04 2023-06-30 13F GOSSAMER BIO PUT Put 3,200 3,100.00 0 n/a n/a n/a
2023-04-27 2023-03-31 13F GOSSAMER BIO PUT Put 100 -99.89 0 n/a n/a n/a
2023-02-02 2022-12-31 13F GOSSAMER BIO PUT Put 94,400 2,045.45 0 -100.00 n/a n/a n/a
2022-11-04 2022-09-30 13F GOSSAMER BIO PUT Put 4,400 633.33 52 940.00 n/a n/a n/a
2022-08-03 2022-06-30 13F GOSSAMER BIO PUT Put 600 5 n/a n/a n/a
2022-05-02 2022-03-31 13F GOSSAMER BIO PUT Put 0 -100.00 0 -100.00 n/a n/a n/a
2022-02-23 2021-12-31 13F/A GOSSAMER BIO PUT Put 4,500 1,400.00 50 2,400.00 n/a n/a n/a
2022-02-04 2021-12-31 13F GOSSAMER BIO PUT Put 300 2 n/a n/a n/a
2021-10-28 2021-09-30 13F GOSSAMER BIO PUT Put 300 0.00 2 0.00 n/a n/a n/a
2021-08-12 2021-06-30 13F GOSSAMER BIO PUT Put 300 1,566.67 2 -87.50 n/a n/a n/a
2021-04-26 2021-03-31 13F GOSSAMER BIO PUT Put 18 -66.67 16 -69.23 n/a n/a n/a
2021-02-02 2020-12-31 13F GOSSAMER BIO PUT Put 54 -35.71 52 -50.00 n/a n/a n/a
2020-10-14 2020-09-30 13F GOSSAMER BIO PUT Put 84 -62.33 104 -64.01 n/a n/a n/a
2020-07-13 2020-06-30 13F GOSSAMER BIO PUT Put 223 -62.46 289 -51.99 n/a n/a n/a
2020-04-29 2020-03-31 13F GOSSAMER BIO PUT Put 594 1,597.14 602 1,014.81 n/a n/a n/a
2020-02-05 2019-12-31 13F GOSSAMER BIO PUT Put 35 -96.79 54 -97.05 n/a n/a n/a
2019-10-15 2019-09-30 13F GOSSAMER BIO PUT Put 1,091 1,831 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.