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SEC Form 4 research

Gossamer Bio, Inc. insider transactions

Inspect Gossamer Bio, Inc.'s public SEC insider acquisitions and sales, reporting owners and source receipts.

As of 2026-10-15T08:02:39.132Z

Issuer CIK
0001728117
Reporting owners
32
Officers and directors
12
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What is a Form 4?

Animation: what a Form 4 is, shown with one real example. Sonic Automotive (SAH) reporting owner Paul P. Rusnak bought 13,701 shares at $59.78 on Wednesday, October 7, 2026, transaction code P, an open-market purchase (S is a sale and A is an award from the company). A timeline marks the SEC's two-business-day filing deadline, which ends Friday, October 9. The SEC accepted the Form 4 at 4:33:21 PM ET on October 9, and NexusTrade treats it as public one minute later, at 4:34:21 PM ET. A lamp for NexusTrade's InsiderTrades indicator stays off from the trade date until that moment, then counts one purchase worth 13,701 × $59.78 = $819,045.78.
In this example the shares were bought on Oct 7, 2026, and NexusTrade's InsiderTrades indicator can count the purchase starting at 4:34:21 PM ET on Oct 9, one minute after the SEC accepted the Form 4.

A Form 4 is the SEC filing a company insider, such as an officer, director or 10% owner, uses to report a trade in the company's stock, generally within two business days. The animation follows one real filing as an example: Paul P. Rusnak's purchase of Sonic Automotive (SAH) shares on October 7, 2026.

The same reading applies to every row on this page. The trade date is when the shares changed hands. The available date is when NexusTrade treats the filing as public, and a NexusTrade InsiderTrades indicator counts a purchase (code P) or sale (code S) only from that moment. Code A awards are not counted as purchases.

Read one actual disclosure before using it

Show the table · 1 row, 7 columns

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2026-09-252026-09-23Milligan SandraA10,000$0Not reported

First displayed source row from Recent insider disclosures. The full bounded history and coverage notes remain below.

The displayed observation date is 2026-09-23 and its public availability date is 2026-09-25. Subtracting those calendar dates gives 2 days of disclosure lag. Historical public research can use the record from the availability date, rather than backdating knowledge to the observation date. The calendar-day difference does not assert an intraday publication time.

This row is code A: a award. An award is an acquisition but is not an open-market purchase. A purchase-following rule must not count it as code P.

Open the linked original receipts to verify the row, then inspect a second record before drawing a pattern. This public filing observation supplies source evidence, not a completed copy-trading return.

SEC accession 0001628280-26-063624 ↗SEC accession 0001628280-26-063619 ↗SEC accession 0001628280-26-063616 ↗

Recent insider disclosures

Inspect all 14 displayed rows: Recent insider disclosures

This table includes purchases, sales and awards in the public filing record. Awards and open-market purchases are distinct transaction codes. For historical research, use the public availability date to determine when the transaction was knowable.

Read code P as a purchase, S as a sale and A as an award. An award is an acquisition, but it is not an open-market purchase. Open the filing receipt to check the transaction details.

Scroll sideways to compare all columns. Select a heading to sort.

2026-09-252026-09-23Milligan SandraA10,000$0Not reported
2026-09-252026-09-23Daniel Thomas OA10,000$0Not reported
2026-09-252026-09-23Ciongoli Gregory AustinA30,000$0Not reported
2026-09-252026-09-23Drynan SkyeA10,000$0Not reported
2026-09-252026-09-23Quisel John DA10,000$0Not reported
2026-09-252026-09-23Cox Russell J.A10,000$0Not reported
2026-09-252026-09-23Nathan Steven DA10,000$0Not reported
2026-08-272026-08-24Smith Robert Paul JRA5,800,051$0Not reported
2026-08-272026-08-24Peterson CarynA5,800,051$0Not reported
2026-08-272026-08-24Giraudo BryanA5,800,051$0Not reported
2026-08-272026-08-24Giraudo BryanA25$1,000Not reported
2026-08-272026-08-24Christian WaageA2,900,026$0Not reported
2026-08-272026-08-24Hasnain FaheemA5,800,051$0Not reported
2026-08-272026-08-24Hasnain FaheemA166$1,000Not reported

Most recent 90-day source activity, up to 50 rows. No rows means no matching recent records, not no historical activity.

Officers and directors in the directory

Inspect all 13 displayed rows: Officers and directors in the directory

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GUJRATHI SHEILA00015752025
Dupont Jakob000155333534
Giraudo Bryan000174084719
Stampacchia Otello0001361712318
Peterson Caryn00018572565
Christian Waage000155317915
Aranda Richard00018678728
Carter Laura00018581787
Cox Russell J.000151298417
Hasnain Faheem000135262055
Milligan Sandra00018598102
Salter-Cid Luisa00017664043
Smith Robert Paul JR00020030591
GUJRATHI SHEILA ↗Dupont Jakob ↗Giraudo Bryan ↗Stampacchia Otello ↗Peterson Caryn ↗Christian Waage ↗Aranda Richard ↗Carter Laura ↗Cox Russell J. ↗Hasnain Faheem ↗Milligan Sandra ↗Salter-Cid Luisa ↗Smith Robert Paul JR ↗

Which transactions qualify for the company tracker

The company strategy uses verified officers and directors with qualifying acquisitions at this issuer. Other reporting owners may appear in source records without becoming strategy signals.

Strategy eligibility is held while filing coverage is unresolved.

Historical follower simulations are separate from these source transactions. They do not establish live trading results.