Who is required to file SEC Form 4?

SEC Form 4 must be filed by any person who is an officer, director, or beneficial owner of more than 10% of a publicly traded company's equity securities. This includes CEOs, CFOs, board members, and any large institutional or individual shareholder crossing the 10% threshold.

Where can I find SEC Form 4 filings?

All Form 4 filings are publicly available on SEC EDGAR at sec.gov/cgi-bin/browse-edgar. InsiderAct also ingests these filings in near real time and presents them in a more readable format at insideract.com/transactions.

What is the penalty for filing Form 4 late?

The SEC can impose civil penalties for late Form 4 filings. While the SEC does not always pursue enforcement for minor delays, repeated or significant late filings can result in fines and draw regulatory attention. Late filings are flagged in EDGAR and visible to investors.

What is the difference between Form 3, Form 4, and Form 5?

Form 3 is an initial disclosure filed when a person first becomes an insider — it establishes their baseline ownership. Form 4 reports changes in ownership and must be filed within 2 business days of a transaction. Form 5 is an annual filing for transactions that were exempt from Form 4 reporting during the year (such as small gifts or inheritance). Form 4 is by far the most frequently filed and most analytically useful.

Does SEC Form 4 apply to foreign companies listed in the US?

Foreign private issuers listed on US exchanges (ADRs) are generally exempt from Form 4 reporting requirements. Instead, they may file Form 20-F or use Form 6-K for material disclosures. This means insider trading data for foreign-listed companies is less comprehensive and less timely than for US domestic issuers. InsiderAct focuses primarily on domestic US issuers where Form 4 coverage is complete.

April 2026·5 min read

What is SEC Form 4? A Plain-English Guide

Every time a company executive, director, or major shareholder buys or sells stock, they're required to report it. SEC Form 4 is that report — and it's public record.

Quick Answer

SEC Form 4 is a mandatory public disclosure filed with the SEC within 2 business days whenever a corporate insider — an officer, director, or 10%+ shareholder — buys or sells company stock. It records the insider's name, role, transaction date, share count, and price. All Form 4 filings are publicly available on SEC EDGAR.

What is SEC Form 4?

SEC Form 4 is a document filed with the U.S. Securities and Exchange Commission (SEC) that discloses changes in the ownership of a company's securities by its insiders. "Insiders" include corporate officers (CEO, CFO, COO), directors, and shareholders who own more than 10% of a company's shares.

The filing is required under Section 16(a) of the Securities Exchange Act of 1934. It must be submitted within two business days of the transaction — so the disclosure is nearly real-time.

Who has to file Form 4?

Three categories of insiders are required to file:

→Officers: CEO, CFO, COO, General Counsel, and other executive officers
→Directors: Board members, whether executive or independent
→10% shareholders: Any person or entity that owns more than 10% of a company's outstanding shares

What information does Form 4 contain?

Each Form 4 filing includes:

→The name and title of the insider
→The company and its stock ticker
→The type of transaction (purchase, sale, award, option exercise)
→The number of shares involved
→The price per share
→The date of the transaction
→The insider's total shares owned after the transaction

Not all Form 4 transactions are equal

Form 4 covers many types of transactions, but they don't all carry the same informational value:

P — Open market purchaseStrong signal

The insider voluntarily bought shares at the market price using their own money. This is the signal most investors focus on.

S — Open market saleWeak signal

Insiders sell for many reasons (taxes, diversification, personal expenses). Selling is generally less informative than buying.

A — Award / grantNone signal

Shares received as compensation. Not a discretionary investment decision.

M — Option exerciseLow signal

Often followed immediately by a sale. Usually reflects compensation mechanics, not a market view.

How do investors use Form 4 data?

Because Form 4 filings are public and nearly real-time, they've become a widely used source for investment research. Investors typically look for:

→Large open-market purchases by C-suite executives
→Multiple insiders buying within the same short period (cluster buying)
→Insider buying after a significant price decline
→Unusually large purchases relative to the insider's salary or existing holdings

The raw filings are available on the SEC's EDGAR database. Tools like InsiderAct parse, filter, and organize this data to surface the patterns most likely to be meaningful — such as cluster buying and large insider purchases.

Browse real Form 4 insider activity

InsiderAct surfaces the most meaningful Form 4 transactions — filtering out awards and option grants to focus on what actually matters: open-market insider buying.

View insider buys →

SEC Form 4 Filing Deadline: When Must Insiders Report? →Legal Insider Trading: What It Is and How to Track It →How to Read Insider Trading Data: A Practical Guide →Insider Buying Strategy: How to Follow Corporate Insiders →Cluster Buying Explained: Why Multiple Insiders Buying Together Matters →