What Is SEC Form 4?

SEC Form 4 is the filing a corporate insider must submit whenever they buy or sell shares of their own company. Officers, directors, and anyone who owns more than 10% of a company's stock are required by law to report the trade to the Securities and Exchange Commission within two business days. Every Form 4 is public, free, and posted on the SEC's EDGAR database the moment it is filed.

In plain terms: it is the paper trail that lets you see exactly when the people who run a company are betting on - or cashing out of - their own stock.

Who has to file a Form 4?

The SEC defines an "insider" as anyone with privileged access to a company. In practice, Form 4 filers are:

• Officers - the CEO, CFO, COO, and other named executives.
• Directors - every member of the board, including independent directors.
• 10% owners - any person or entity holding more than 10% of the company's shares, such as an activist fund or founding family.

These people have legal access to material nonpublic information, so their trades are tightly regulated and must be disclosed almost immediately. That transparency is the whole point - and it is what makes the data usable.

Form 3 vs Form 4 vs Form 5

Form 4 is part of a small family of insider ownership filings. They are easy to mix up:

Form	What it reports	When
Form 3	An insider's initial statement of holdings when they first become an insider.	Within 10 days of becoming an insider
Form 4	A change in an insider's holdings - the actual buys and sells.	Within 2 business days of the trade
Form 5	An annual catch-up for smaller transactions that were exempt from Form 4.	Within 45 days of fiscal year-end

For investors watching insider activity, Form 4 is the one that matters - it is timely (two days) and it captures the discretionary open-market trades that carry a signal.

What's on a Form 4?

A Form 4 has two transaction tables: Table I for stock (open-market buys and sells) and Table II for derivatives (options, warrants, convertible notes). Each row records the transaction date, the number of shares, the price, and the total the insider owns afterward. The single most important field is the transaction code - one letter that tells you whether the trade was a genuine purchase, a routine sale, a stock grant, or a tax withholding.

We break the whole filing down field by field in how to read an SEC Form 4, and every code is decoded in SEC Form 4 transaction codes explained.

Why Form 4 matters to investors

Insiders know their business better than any outside analyst. When one of them takes personal money and buys stock on the open market - transaction code P - they are making an informed bet that nobody forced them to make. Decades of research show that open-market insider buying, especially when several insiders buy at once, has tended to precede above-average returns.

The catch is that most of what appears on Form 4 is not a conviction signal. Grants, option exercises, and tax withholdings all show up on the same form and drown out the meaningful trades. Sorting the signal from the noise is exactly the problem InsiderTape solves. To go deeper on the signal itself, see is insider buying bullish and what cluster buying is.

Where to find Form 4 filings

Every Form 4 is available for free on the SEC's EDGAR system at sec.gov, searchable by company or by individual filer. The raw filings, though, are built for compliance, not analysis - they are hard to scan, impossible to compare across companies, and full of transactions that don't matter. That is why InsiderTape ingests every filing in real time, strips out the noise, and surfaces the open-market buys and sells worth watching.