What SEC filings does C4 Therapeutics, Inc. submit to the SEC?

C4 Therapeutics, Inc. (CCCC) 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 CCCC?

A Form 4 for CCCC 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 C4 Therapeutics, 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 CCCC?

The 10-K is C4 Therapeutics, 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 CCCC SEC filings directly on EDGAR?

You can view all historical C4 Therapeutics, Inc. filings on the SEC EDGAR company page for CCCC. Each filing card on this page links directly to the original SEC document.

How often does C4 Therapeutics, Inc. file with the SEC?

C4 Therapeutics, 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 CCCC shares. 8-K filings occur whenever a material event happens — which can be several times per quarter for an active company.

CCCC SEC Filing News — C4 Therapeutics, Inc.

Latest SEC filings for C4 Therapeutics, Inc. (CCCC) 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: 2026-10-02.

C4 Therapeutics, Inc., a clinical-stage biopharmaceutical company, develops novel therapeutic candidates to degrade disease-causing proteins. Its lead product candidate is Cemsidomide, an orally bioavailable monodac targeting IKZF1 and IKZF3, or IKZF1/3 to address a need across multiple lines of therapy in multiple myeloma, which has competed its phase 1. The company is also developing oncology product candidate, CFT8919, an orally bioavailable, allosteric, mutant-selective bidac degrader of epi…

Sector: Healthcare Industry: Biotechnology Market Cap: $355.5M CIK: 1662579

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 C4 Therapeutics, 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.

CCCC Filing Activity Snapshot 2026-06-26 — 2026-10-02

Insider Transactions (Form 4)

0 buys vs 0 sells

Insider buying and selling activity is balanced in this period.

Largest Form 144 Filing

$1.90M

JAY GELDMACHER · 2026-08-14

82,563 shares · Form 144

Form 144 Notices

Proposed insider sales filed — Form 144 is a notice of intent, not a confirmed transaction. Actual sales are confirmed via Form 4.

Insider Transactions 13 · 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 13 filings in this group are Form 4s for C4 Therapeutics, 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 13 insider filings shown, the breakdown is 12 compensation award and 1 option exercise. 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.
Option exercise ×1: The insider converted options into shares. The exercise price was fixed when the options were granted, so the timing usually tracks an expiry schedule.

Form 4 Compensation award Tax / Compensation Filing 2026-10-02

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

Anderson Kenneth Carl (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	3,662	$3.14	$11.5K

Filing: Form 4 (Insider Transaction) Insider: Anderson Kenneth Carl (Director) Shares: 3,662

View on SEC EDGAR → Open Filing Document →

Form 4 Compensation award Tax / Compensation Filing 2026-10-02

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

GROGAN DONNA ROY (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	4,618	$3.14	$14.5K

Filing: Form 4 (Insider Transaction) Insider: GROGAN DONNA ROY (Director) Shares: 4,618

View on SEC EDGAR → Open Filing Document →

Form 4 Option exercise Tax / Compensation Filing 2026-07-13

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

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

The insider converted options into shares. The exercise price was fixed when the options were granted, so the timing usually tracks an expiry schedule.

Transactions reported on this filing
Code	Nature	Shares	Price	Value
`M`	Option exercise	15,325	—	—
`F`	Tax withholding on vested shares	7,397	$4.06	$30.0K

Filing: Form 4 (Insider Transaction) Insider: REYNO LEONARD (Chief Medical Officer) Shares: 22,722

View on SEC EDGAR → Open Filing Document →

Form 4 Compensation award Tax / Compensation Filing 2026-07-02

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

Anderson Kenneth Carl (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	2,650	$4.34	$11.5K

Filing: Form 4 (Insider Transaction) Insider: Anderson Kenneth Carl (Director) Shares: 2,650

View on SEC EDGAR → Open Filing Document →

Form 4 Compensation award Tax / Compensation Filing 2026-07-02

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

GROGAN DONNA ROY (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	3,341	$4.34	$14.5K

Filing: Form 4 (Insider Transaction) Insider: GROGAN DONNA ROY (Director) Shares: 3,341

View on SEC EDGAR → Open Filing Document →

Form 4 Compensation award Tax / Compensation Filing 2026-06-26

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

Hughes Owen (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)	62,000	—	—

Filing: Form 4 (Insider Transaction) Insider: Hughes Owen (Director)

View on SEC EDGAR → Open Filing Document →

Form 4 Compensation award Tax / Compensation Filing 2026-06-26

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

Hoerter Steven L. (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)	62,000	—	—

Filing: Form 4 (Insider Transaction) Insider: Hoerter Steven L. (Director)

View on SEC EDGAR → Open Filing Document →

Form 4 Compensation award Tax / Compensation Filing 2026-06-26

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

Koppikar Utpal (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)	62,000	—	—

Filing: Form 4 (Insider Transaction) Insider: Koppikar Utpal (Director)

View on SEC EDGAR → Open Filing Document →

Form 4 Compensation award Tax / Compensation Filing 2026-06-26

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

Anderson Kenneth Carl (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)	62,000	—	—

Filing: Form 4 (Insider Transaction) Insider: Anderson Kenneth Carl (Director)

View on SEC EDGAR → Open Filing Document →

Form 4 Compensation award Tax / Compensation Filing 2026-06-26

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

Cooper Ronald Harold Wilfred (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)	62,000	—	—

Filing: Form 4 (Insider Transaction) Insider: Cooper Ronald Harold Wilfred (Director)

View on SEC EDGAR → Open Filing Document →

Form 4 Compensation award Tax / Compensation Filing 2026-06-26

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

Bessen Laura (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)	62,000	—	—

Filing: Form 4 (Insider Transaction) Insider: Bessen Laura (Director)

View on SEC EDGAR → Open Filing Document →

Form 4 Compensation award Tax / Compensation Filing 2026-06-26

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

Fawell Stephen (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)	62,000	—	—

Filing: Form 4 (Insider Transaction) Insider: Fawell Stephen (Director)

View on SEC EDGAR → Open Filing Document →

Form 4 Compensation award Tax / Compensation Filing 2026-06-26

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

GROGAN DONNA ROY (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)	62,000	—	—

Filing: Form 4 (Insider Transaction) Insider: GROGAN DONNA ROY (Director)

View on SEC EDGAR → Open Filing Document →

Proposed Insider Sales 4 · Form 144

A Form 144 is a notice of intent to sell restricted or control securities. It is not a record that anything was sold. C4 Therapeutics, Inc. has 4 such notices in this period.

The distinction matters because a Form 144 is frequently reported as though it were a completed insider sale. The filer may sell all of the shares covered, some of them, or none at all, and there is no obligation to update the notice either way. A sale that is actually executed by an officer or director shows up separately on a Form 4, which is the filing to check before treating a proposed sale as a real one.

Form 144 Proposed Insider Sale 2026-08-14

CCCC Form 144 filed for proposed insider sale by Mark Mossler (4,139 shares) ~$17.6K

Mark Mossler filed a Form 144 with the SEC indicating intent to sell CCCC (C4 Therapeutics, Inc.) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4.

Filing: Form 144 (Proposed Sale Notice) Insider: Mark Mossler Shares: 4,139 Est. Value: $17.6K

View on SEC EDGAR → Open Filing Document →

Form 144 Proposed Insider Sale 2026-08-14

CCCC Form 144 filed for proposed insider sale by JAY GELDMACHER (82,563 shares) ~$1.90M

JAY GELDMACHER filed a Form 144 with the SEC indicating intent to sell CCCC (C4 Therapeutics, Inc.) shares. Form 144 reflects a proposed sale, not a completed transaction. The actual execution, if any, would typically appear later in a Form 4.

Filing: Form 144 (Proposed Sale Notice) Insider: JAY GELDMACHER Shares: 82,563 Est. Value: $1.90M

View on SEC EDGAR → Open Filing Document →

Form 144 Proposed Insider Sale 2026-08-13

CCCC Form 144 filed for proposed insider sale by Mark Mossler (15,000 shares) ~$61.1K

Filing: Form 144 (Proposed Sale Notice) Insider: Mark Mossler Shares: 15,000 Est. Value: $61.1K

View on SEC EDGAR → Open Filing Document →

Form 144 Proposed Insider Sale 2026-08-12

CCCC Form 144 filed for proposed insider sale by Mark Mossler (19,519 shares) ~$76.7K

Filing: Form 144 (Proposed Sale Notice) Insider: Mark Mossler Shares: 19,519 Est. Value: $76.7K

View on SEC EDGAR → Open Filing Document →

Material Events 2 · Form 8-K

An 8-K reports a material event in the window between scheduled reports. There are 2 in this period for C4 Therapeutics, 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 2026-09-25

CCCC filed 8-K — material company event

C4 Therapeutics, 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 2026-08-11

CCCC filed 8-K — material company event

C4 Therapeutics, 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 →

Periodic Reports 1 · Forms 10-K and 10-Q

The periodic reports are where the audited and reviewed financial statements live. This period contains 1 quarterly report (10-Q) for C4 Therapeutics, Inc.

The two are not equivalent in weight. A 10-K is audited by an external firm and includes the full risk factor disclosure, business description and management discussion; a 10-Q is unaudited, reviewed rather than examined, and much shorter. When a figure in a quarterly report is later revised, the annual report is usually where the correction appears.

An amended report — 10-K/A or 10-Q/A — restates or corrects something in the original filing, and is worth reading against the version it replaces.

Form 10-Q Quarterly Report 2026-08-11

CCCC filed Quarterly Report (10-Q)

C4 Therapeutics, Inc. filed its quarterly report with the SEC. This report includes unaudited financial statements and management discussion for the quarter.

Filing: 10-Q (Quarterly Report)

View on SEC EDGAR → Open Filing Document →

How we classify C4 Therapeutics, 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 CCCC. Read these alongside the fundamentals rather than in isolation.

Frequently Asked Questions — CCCC SEC Filings

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CCCC 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.

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