Gossamer Bio, Inc.
US ˙ NasdaqGS ˙ US38341P1021

SecurityGOSS / Gossamer Bio, Inc.
InstitutionMorgan Stanley
Latest Disclosed Ownership367,378 shares
Latest Disclosed Value $ 120,684
Morgan Stanley reports 60.02% decrease in ownership of GOSS / Gossamer Bio, Inc.

On May 15, 2026 - Morgan Stanley filed a 13F-HR form disclosing ownership of 367,378 shares of Gossamer Bio, Inc. (US:GOSS) valued at $120,684 USD as of March 31, 2026. The entity filed a previous 13F-HR/A on May 27, 2026 disclosing 918,888 shares of Gossamer Bio, Inc.. This represents a change in shares of -60.02% during the quarter. The current value of the position is $65,320 USD.

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)
2026-05-15 2026-03-31 13F GOSSAMER BIO COM 38341P102 367,378 -551,510 -60.02 121 -95.79 0.0000
2026-05-27 2025-12-31 13F/A-1 GOSSAMER BIO COM 38341P102 918,888 352,469 62.23 2,849 91.27 0.0002
2026-02-13 2025-12-31 13F GOSSAMER BIO COM 38341P102 918,888 352,469 2,849 0.0002
2026-05-27 2025-09-30 13F/A-1 GOSSAMER BIO COM 38341P102 566,419 -252,272 -30.81 1,490 48.01 0.0001
2025-11-14 2025-09-30 13F GOSSAMER BIO COM 38341P102 566,419 -252,272 1,490 0.0001
2025-08-15 2025-06-30 13F GOSSAMER BIO COM 38341P102 818,691 359,158 78.16 1,007 99.21 0.0001
2025-05-15 2025-03-31 13F GOSSAMER BIO COM 38341P102 459,533 310,978 209.34 505 276.87 0.0000
2025-05-15 2024-12-31 13F/A-1 GOSSAMER BIO COM 38341P102 148,555 -31,680 -17.58 134 -24.29 0.0000
2025-02-14 2024-12-31 13F GOSSAMER BIO COM 38341P102 148,555 -31,680 134 0.0000
2025-05-14 2024-09-30 13F/A-2 GOSSAMER BIO COM 38341P102 180,235 -14,429 -7.41 178 1.14 0.0000
2025-02-14 2024-09-30 13F/A-1 GOSSAMER BIO COM 38341P102 180,235 -14,429 178 0.0000
2024-11-14 2024-09-30 13F GOSSAMER BIO COM 38341P102 180,235 -14,429 178 0.0000
2025-05-14 2024-06-30 13F/A-2 GOSSAMER BIO COM 38341P102 194,664 -4,140,436 -95.51 175 -96.58 0.0000
2024-10-17 2024-06-30 13F/A-1 GOSSAMER BIO COM 38341P102 194,664 -4,140,436 175 0.0000
2024-08-14 2024-06-30 13F GOSSAMER BIO COM 38341P102 194,664 -4,140,436 175 0.0000
2024-10-17 2024-03-31 13F/A-2 GOSSAMER BIO COM 38341P102 4,335,100 -1,233,772 -22.15 5,115 0.67 0.0004
2024-08-16 2024-03-31 13F/A-1 GOSSAMER BIO COM 38341P102 4,335,100 -1,233,772 5,115 0.0004
2024-05-15 2024-03-31 13F GOSSAMER BIO COM 38341P102 4,335,100 -1,233,772 5,115 0.0004
2024-08-16 2023-12-31 13F/A-1 GOSSAMER BIO COM 38341P102 5,568,872 5,177,501 1,322.91 5,082 1,463.38 0.0004
2024-02-13 2023-12-31 13F GOSSAMER BIO COM 38341P102 5,568,872 5,177,501 5,082 0.0004
2023-11-15 2023-09-30 13F GOSSAMER BIO COM 38341P102 391,371 -184,889 -32.08 326 -52.97 0.0000
2023-08-14 2023-06-30 13F GOSSAMER BIO COM 38341P102 576,260 -193,550 -25.14 692 -28.69 0.0001
2023-05-15 2023-03-31 13F GOSSAMER BIO COM 38341P102 769,810 -2,393,535 -75.66 970 -85.88 0.0001
2023-02-14 2022-12-31 13F GOSSAMER BIO COM 38341P102 3,163,345 1,955,742 161.95 6,864 -52.55 0.0008
2022-11-14 2022-09-30 13F GOSSAMER BIO COM 38341P102 1,207,603 -169,661 -12.32 14,467 25.49 0.0020
2022-10-27 2022-06-30 13F/A-1 GOSSAMER BIO COM 38341P102 1,377,264 84,709 6.55 11,528 2.75 0.0015
2022-08-15 2022-06-30 13F GOSSAMER BIO COM 38341P102 1,377,264 84,709 11,528 0.0003
2022-10-27 2022-03-31 13F/A-1 GOSSAMER BIO COM 38341P102 1,292,555 70,700 5.79 11,219 -18.82 0.0015
2022-05-13 2022-03-31 13F GOSSAMER BIO COM 38341P102 1,292,555 70,700 11,219 0.0015
2022-02-14 2021-12-31 13F GOSSAMER BIO COM 38341P102 1,221,855 967,952 381.23 13,820 332.96 0.0017
2021-11-15 2021-09-30 13F GOSSAMER BIO COM 38341P102 253,903 -54,842 -17.76 3,192 27.32 0.0004
2021-08-23 2021-06-30 13F/A-1 GOSSAMER BIO COM 38341P102 308,745 -20,216 -6.15 2,507 -17.61 0.0003
2021-08-16 2021-06-30 13F GOSSAMER BIO COM 38341P102 308,745 -20,216 2,507 0.0001
2021-05-17 2021-03-31 13F GOSSAMER BIO COM 38341P102 328,961 -18,243 -5.25 3,043 -9.38 0.0004
2021-02-16 2020-12-31 13F GOSSAMER BIO COM 38341P102 347,204 148,418 74.66 3,358 36.17 0.0005
2020-11-13 2020-09-30 13F GOSSAMER BIO COM 38341P102 198,786 -180,065 -47.53 2,466 -49.93 0.0005
2020-08-14 2020-06-30 13F GOSSAMER BIO COM 38341P102 378,851 186,713 97.18 4,925 152.56 0.0011
2020-05-26 2020-03-31 13F/A-1 GOSSAMER BIO COM 38341P102 192,138 106,427 124.17 1,950 45.52 0.0005
2020-05-15 2020-03-31 13F GOSSAMER BIO COM 38341P102 192,138 106,427 1,950 149.8007
2020-02-14 2019-12-31 13F GOSSAMER BIO COM 38341P102 85,711 -30,307 -26.12 1,340 -31.21 0.0003
2019-11-14 2019-09-30 13F GOSSAMER BIO COM 38341P102 116,018 114,921 10,475.93 1,948 8,016.67 0.0005
2019-08-14 2019-06-30 13F GOSSAMER BIO COM 38341P102 1,097 -1,005 -47.81 24 -47.83 0.0000
2019-05-15 2019-03-31 13F GOSSAMER BIO COM 38341P102 2,102 2,102 46 0.0000
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.