What SEC filings does Gossamer Bio, Inc. submit to the SEC?

Gossamer Bio, Inc. (GOSS) submits several types of SEC filings including Form 4 (insider transactions), Form 144 (proposed insider sales), 8-K reports (material events such as earnings releases, acquisitions, leadership changes), and periodic reports — the 10-Q (quarterly) and 10-K (annual). All filings are publicly available through SEC EDGAR.

What does a Form 4 filing tell me about GOSS?

A Form 4 for GOSS discloses a transaction by a company insider — typically a director, officer, or 10%+ shareholder. It shows the source-reported date, number of shares, price, and updated ownership. These facts do not establish motive or predict future returns.

How do I interpret an 8-K filing from Gossamer Bio, Inc.?

An 8-K signals a material event requiring prompt disclosure. Common triggers include earnings pre-announcements, acquisitions, leadership appointments or departures, credit changes, or regulatory actions. Read the item codes inside the filing to understand exactly what was disclosed before drawing conclusions.

What is the difference between a 10-K and 10-Q for GOSS?

The 10-K is Gossamer Bio, Inc.'s annual report with fully audited financial statements, comprehensive MD&A, and complete risk factor disclosures — filed 60–90 days after fiscal year-end. The 10-Q is a lighter quarterly report with unaudited financials filed for the first three quarters. Together they provide a continuous financial picture of the company.

Where can I see all GOSS SEC filings directly on EDGAR?

You can view all historical Gossamer Bio, Inc. filings on the SEC EDGAR company page for GOSS. Each filing card on this page links directly to the original SEC document.

How often does Gossamer Bio, Inc. file with the SEC?

Gossamer Bio, Inc. files one 10-K per year and up to three 10-Qs per year. Form 4 insider transactions must be reported within two business days of each trade, so the frequency depends on how often insiders are buying or selling GOSS shares. 8-K filings occur whenever a material event happens — which can be several times per quarter for an active company.

GOSS SEC Filing News — Gossamer Bio, Inc.

Latest SEC filings for Gossamer Bio, Inc. (GOSS) explained in plain English. Covers insider buying and selling (Form 4), proposed insider sales (Form 144), material company events (8-K), and quarterly & annual reports (10-Q / 10-K). StrongBuyAnalytics provides navigation and brief excerpts or summaries; original filings remain at the SEC/source links and were authored by their filers, not StrongBuyAnalytics. Filing dates shown are source dates. Coverage and detection can be delayed or incomplete because of SEC availability, amendments, parsing, caching, or outages. Latest source filing date shown: 2026-09-28.

Gossamer Bio, Inc., a clinical-stage biopharmaceutical company, focuses on developing and commercializing seralutinib for the treatment of pulmonary hypertension and pulmonary arterial hypertension in the United States. The company develops GB002, an inhaled, small molecule, platelet-derived growth factor receptor, or PDGFR, colony-stimulatin factor 1 receptor and c-KIT inhibitor, which is in Phase 3 clinical trial for the treatment of PAH. It has license agreements with Pulmokine, Inc. to devel…

Sector: Healthcare Industry: Biotechnology Market Cap: $51.6M CIK: 1728117

Total Filings

Bullish Classifications

Bearish Classifications

Insider Transactions

Material Events (8-K)

Periodic Reports

What you're looking at: Each item below is parsed from an actual SEC filing submitted by Gossamer Bio, Inc.. Form 4 = confirmed insider transaction · Form 144 = proposed sale notice · 8-K = material event (earnings, M&A, leadership change, etc.) · 10-Q / 10-K = quarterly / annual report.

GOSS Filing Activity Snapshot 2026-08-21 — 2026-09-28

Insider Transactions (Form 4)

0 buys vs 0 sells

Insider buying and selling activity is balanced in this period.

Insider Transactions 12 · Forms 3, 4 and 5

A Form 4 is filed within two business days of a company insider — an officer, a director, or a holder of more than ten percent of the stock — changing their position in the shares. All 12 filings in this group are Form 4s for Gossamer Bio, Inc.

The difficulty with reading these filings as a group is that a single form type covers transactions that mean entirely different things. An executive spending their own money to buy stock and an executive having shares withheld to pay tax on a vesting grant both appear as a Form 4. Every filing below is therefore tagged with the nature of the underlying transaction, taken from the transaction code reported on the form itself.

Across the 12 insider filings shown, the breakdown is 12 compensation award. None of the classified filings involved a discretionary open-market trade, so this period says nothing about what insiders think of the price.

What each transaction type means

Compensation award ×12: Shares were granted as compensation rather than purchased. No cash changed hands, so the filing reflects a pay decision by the company, not a judgement about the price.

Form 4 Compensation award Tax / Compensation Filing 2026-09-25

GOSS insider Form 4 filed for equity award, exercise, or tax withholding

Milligan Sandra (Director) filed a Form 4 covering compensation-related activity such as stock awards, option exercises, conversions, or tax withholding. These filings are usually neutral.

Shares were granted as compensation rather than purchased. No cash changed hands, so the filing reflects a pay decision by the company, not a judgement about the price.

Transactions reported on this filing
Code	Nature	Shares	Price	Value
`A`	Compensation award derivative · Stock Option (Right to Buy)	10,000	—	—

Filing: Form 4 (Insider Transaction) Insider: Milligan Sandra (Director)

View on SEC EDGAR → Open Filing Document →

Form 4 Compensation award Tax / Compensation Filing 2026-09-25

GOSS insider Form 4 filed for equity award, exercise, or tax withholding

Daniel Thomas O (Director) filed a Form 4 covering compensation-related activity such as stock awards, option exercises, conversions, or tax withholding. These filings are usually neutral.

Shares were granted as compensation rather than purchased. No cash changed hands, so the filing reflects a pay decision by the company, not a judgement about the price.

Transactions reported on this filing
Code	Nature	Shares	Price	Value
`A`	Compensation award derivative · Stock Option (Right to Buy)	10,000	—	—

Filing: Form 4 (Insider Transaction) Insider: Daniel Thomas O (Director)

View on SEC EDGAR → Open Filing Document →

Form 4 Compensation award Tax / Compensation Filing 2026-09-25

GOSS insider Form 4 filed for equity award, exercise, or tax withholding

Ciongoli Gregory Austin (Director) filed a Form 4 covering compensation-related activity such as stock awards, option exercises, conversions, or tax withholding. These filings are usually neutral.

Shares were granted as compensation rather than purchased. No cash changed hands, so the filing reflects a pay decision by the company, not a judgement about the price.

Transactions reported on this filing
Code	Nature	Shares	Price	Value
`A`	Compensation award derivative · Stock Option (Right to Buy)	30,000	—	—

Filing: Form 4 (Insider Transaction) Insider: Ciongoli Gregory Austin (Director)

View on SEC EDGAR → Open Filing Document →

Form 4 Compensation award Tax / Compensation Filing 2026-09-25

GOSS insider Form 4 filed for equity award, exercise, or tax withholding

Drynan Skye (Director) filed a Form 4 covering compensation-related activity such as stock awards, option exercises, conversions, or tax withholding. These filings are usually neutral.

Shares were granted as compensation rather than purchased. No cash changed hands, so the filing reflects a pay decision by the company, not a judgement about the price.

Transactions reported on this filing
Code	Nature	Shares	Price	Value
`A`	Compensation award derivative · Stock Option (Right to Buy)	10,000	—	—

Filing: Form 4 (Insider Transaction) Insider: Drynan Skye (Director)

View on SEC EDGAR → Open Filing Document →

Form 4 Compensation award Tax / Compensation Filing 2026-09-25

GOSS insider Form 4 filed for equity award, exercise, or tax withholding

Quisel John D (Director) filed a Form 4 covering compensation-related activity such as stock awards, option exercises, conversions, or tax withholding. These filings are usually neutral.

Shares were granted as compensation rather than purchased. No cash changed hands, so the filing reflects a pay decision by the company, not a judgement about the price.

Transactions reported on this filing
Code	Nature	Shares	Price	Value
`A`	Compensation award derivative · Stock Option (Right to Buy)	10,000	—	—

Filing: Form 4 (Insider Transaction) Insider: Quisel John D (Director)

View on SEC EDGAR → Open Filing Document →

Form 4 Compensation award Tax / Compensation Filing 2026-09-25

GOSS insider Form 4 filed for equity award, exercise, or tax withholding

Cox Russell J. (Director) filed a Form 4 covering compensation-related activity such as stock awards, option exercises, conversions, or tax withholding. These filings are usually neutral.

Shares were granted as compensation rather than purchased. No cash changed hands, so the filing reflects a pay decision by the company, not a judgement about the price.

Transactions reported on this filing
Code	Nature	Shares	Price	Value
`A`	Compensation award derivative · Stock Option (Right to Buy)	10,000	—	—

Filing: Form 4 (Insider Transaction) Insider: Cox Russell J. (Director)

View on SEC EDGAR → Open Filing Document →

Form 4 Compensation award Tax / Compensation Filing 2026-09-25

GOSS insider Form 4 filed for equity award, exercise, or tax withholding

Nathan Steven D (Director) filed a Form 4 covering compensation-related activity such as stock awards, option exercises, conversions, or tax withholding. These filings are usually neutral.

Shares were granted as compensation rather than purchased. No cash changed hands, so the filing reflects a pay decision by the company, not a judgement about the price.

Transactions reported on this filing
Code	Nature	Shares	Price	Value
`A`	Compensation award derivative · Stock Option (Right to Buy)	10,000	—	—

Filing: Form 4 (Insider Transaction) Insider: Nathan Steven D (Director)

View on SEC EDGAR → Open Filing Document →

Form 4 Compensation award Tax / Compensation Filing 2026-08-26

GOSS insider Form 4 filed for equity award, exercise, or tax withholding

Christian Waage (EVP, Tech Ops and Admin) filed a Form 4 covering compensation-related activity such as stock awards, option exercises, conversions, or tax withholding. These filings are usually neutral.

Shares were granted as compensation rather than purchased. No cash changed hands, so the filing reflects a pay decision by the company, not a judgement about the price.

Transactions reported on this filing
Code	Nature	Shares	Price	Value
`A`	Compensation award derivative · Stock Option (Right to Buy)	2,900,026	—	—

Filing: Form 4 (Insider Transaction) Insider: Christian Waage (EVP, Tech Ops and Admin)

View on SEC EDGAR → Open Filing Document →

Form 4 Compensation award Tax / Compensation Filing 2026-08-26

GOSS insider Form 4 filed for equity award, exercise, or tax withholding

Peterson Caryn (Chief Development Officer) filed a Form 4 covering compensation-related activity such as stock awards, option exercises, conversions, or tax withholding. These filings are usually neutral.

Shares were granted as compensation rather than purchased. No cash changed hands, so the filing reflects a pay decision by the company, not a judgement about the price.

Transactions reported on this filing
Code	Nature	Shares	Price	Value
`A`	Compensation award derivative · Stock Option (Right to Buy)	5,800,051	—	—

Filing: Form 4 (Insider Transaction) Insider: Peterson Caryn (Chief Development Officer)

View on SEC EDGAR → Open Filing Document →

Form 4 Compensation award Tax / Compensation Filing 2026-08-26

GOSS insider Form 4 filed for equity award, exercise, or tax withholding

Smith Robert Paul JR (Chief Commercial Officer) filed a Form 4 covering compensation-related activity such as stock awards, option exercises, conversions, or tax withholding. These filings are usually neutral.

Shares were granted as compensation rather than purchased. No cash changed hands, so the filing reflects a pay decision by the company, not a judgement about the price.

Transactions reported on this filing
Code	Nature	Shares	Price	Value
`A`	Compensation award derivative · Stock Option (Right to Buy)	5,800,051	—	—

Filing: Form 4 (Insider Transaction) Insider: Smith Robert Paul JR (Chief Commercial Officer)

View on SEC EDGAR → Open Filing Document →

Form 4 Compensation award Tax / Compensation Filing 2026-08-26

GOSS insider Form 4 filed for equity award, exercise, or tax withholding

Giraudo Bryan (COO/CFO) filed a Form 4 covering compensation-related activity such as stock awards, option exercises, conversions, or tax withholding. These filings are usually neutral.

Shares were granted as compensation rather than purchased. No cash changed hands, so the filing reflects a pay decision by the company, not a judgement about the price.

Transactions reported on this filing
Code	Nature	Shares	Price	Value
`A`	Compensation award derivative · Pre-Funded Warrant (Right to Buy)	25	$1,000.00	$25.0K
`A`	Compensation award derivative · Stock Option (Right to Buy)	5,800,051	—	—

Filing: Form 4 (Insider Transaction) Insider: Giraudo Bryan (COO/CFO)

View on SEC EDGAR → Open Filing Document →

Form 4 Compensation award Tax / Compensation Filing 2026-08-26

GOSS insider Form 4 filed for equity award, exercise, or tax withholding

Hasnain Faheem (Director, President & CEO) filed a Form 4 covering compensation-related activity such as stock awards, option exercises, conversions, or tax withholding. These filings are usually neutral.

Shares were granted as compensation rather than purchased. No cash changed hands, so the filing reflects a pay decision by the company, not a judgement about the price.

Transactions reported on this filing
Code	Nature	Shares	Price	Value
`A`	Compensation award derivative · Pre-Funded Warrant (Right to Buy)	166	$1,000.00	$166.0K
`A`	Compensation award derivative · Stock Option (Right to Buy)	5,800,051	—	—

Filing: Form 4 (Insider Transaction) Insider: Hasnain Faheem (Director, President & CEO)

View on SEC EDGAR → Open Filing Document →

Material Events 8 · Form 8-K

An 8-K reports a material event in the window between scheduled reports. There are 8 in this period for Gossamer Bio, Inc. Each 8-K names the item number it is filed under, and that number is the fastest way to tell a routine disclosure from a consequential one.

Item 2.02 is an earnings release, Item 5.02 is a change of directors or officers, and Item 1.01 or 2.01 covers a material agreement or a completed acquisition. Item 7.01 and Item 8.01 are the general-purpose disclosure items and carry no fixed meaning on their own.

Form 8-K Material Company Update 2026-09-28

GOSS filed 8-K — material company event

Gossamer Bio, Inc. filed an 8-K with the SEC reporting a material event. Summary unavailable — view the original SEC filing for the full text.

Filing: 8-K (Material Event)

View on SEC EDGAR → Open Filing Document →

Form 8-K Material Company Update 2026-09-23

GOSS filed 8-K — material company event

Gossamer Bio, Inc. filed an 8-K with the SEC reporting a material event. Summary unavailable — view the original SEC filing for the full text.

Filing: 8-K (Material Event)

View on SEC EDGAR → Open Filing Document →

Form 8-K Material Company Update 2026-09-16

GOSS filed 8-K — material company event

Gossamer Bio, Inc. filed an 8-K with the SEC reporting a material event. Summary unavailable — view the original SEC filing for the full text.

Filing: 8-K (Material Event)

View on SEC EDGAR → Open Filing Document →

Form 8-K Material Company Update 2026-09-11

GOSS filed 8-K — material company event

Gossamer Bio, Inc. filed an 8-K with the SEC reporting a material event. Summary unavailable — view the original SEC filing for the full text.

Filing: 8-K (Material Event)

View on SEC EDGAR → Open Filing Document →

Form 8-K Material Company Update 2026-09-09

GOSS filed 8-K — material company event

Gossamer Bio, Inc. filed an 8-K with the SEC reporting a material event. Summary unavailable — view the original SEC filing for the full text.

Filing: 8-K (Material Event)

View on SEC EDGAR → Open Filing Document →

Form 8-K Material Company Update 2026-09-03

GOSS filed 8-K — material company event

Gossamer Bio, Inc. filed an 8-K with the SEC reporting a material event. Summary unavailable — view the original SEC filing for the full text.

Filing: 8-K (Material Event)

View on SEC EDGAR → Open Filing Document →

Form 8-K Material Company Update 2026-08-26

GOSS filed 8-K — material company event

Gossamer Bio, Inc. filed an 8-K with the SEC reporting a material event. Summary unavailable — view the original SEC filing for the full text.

Filing: 8-K (Material Event)

View on SEC EDGAR → Open Filing Document →

Form 8-K Material Company Update 2026-08-21

GOSS filed 8-K — material company event

Gossamer Bio, Inc. filed an 8-K with the SEC reporting a material event. Summary unavailable — view the original SEC filing for the full text.

Filing: 8-K (Material Event)

View on SEC EDGAR → Open Filing Document →

How we classify Gossamer Bio, Inc.'s filings

Straight from EDGAR

Each displayed record links to an original source document. StrongBuyAnalytics provides navigation and brief excerpts or summaries, not the filing itself. Parsing may omit context or contain errors, so read the original document in full.

Transaction codes, not guesswork

The nature shown on each insider filing comes from the transaction code the filer entered on the form itself — P for an open-market purchase, A for a compensation award, F for shares withheld to pay tax, M for an option exercise. Where one filing contains several codes, the transaction table lists them line by line.

Why the distinction matters

Insider activity is routinely summarised as buying or selling, which flattens together decisions that mean very different things. Shares withheld for tax on a vesting grant are an automatic administrative step; shares bought on the open market are someone committing their own money at the current price.

What this page does not tell you

A filing records what happened, not why. Form 4 does not always disclose whether a sale was executed under a pre-arranged Rule 10b5-1 plan, and no single filing is a basis for a decision on GOSS. Read these alongside the fundamentals rather than in isolation.

Frequently Asked Questions — GOSS SEC Filings

More Tools for GOSS

GOSS Full Stock Analysis GOSS Live Chart Institutional Ownership Earnings Calendar Options Flow Scanner Semiconductor Demand Zone Tracker Sector Scanner Browse All Stocks

Want deeper GOSS analysis?

View valuation, growth metrics, the rule-based stock-page score, demand zones, peer comparison, and more — all on the GOSS stock analysis page.

GOSS Full Analysis

Publisher, sources & limitations — September 15, 2026. StrongBuyAnalytics provides navigation and brief excerpts or summaries for educational use. Original filings remain at SEC EDGAR or other displayed source links; StrongBuyAnalytics does not author them. Filing dates are source dates, not publication dates for this page. Coverage can be delayed, incomplete, amended, or unavailable because of SEC/source availability, parsing, caching, or outages. Verify every material statement in the original filing.

Data Sources · Methodology · AI Disclosure · Corrections Policy · Disclaimer