How to Read an SEC Form 4 (Insider Trading Filing): A Complete Guide

The Form 4 is where every insider trade is disclosed. Here's how to actually read one.

Updated June 11, 2026 · ClearOcean Research

Every time a corporate insider buys or sells their own company's stock, they must tell the SEC — usually within two business days — on a document called a Form 4. These filings are public, free, and the raw material behind every "insider just bought" headline. Learning to read one yourself cuts out the middleman.

Who has to file

Form 4 obligations fall on a company's officers, directors, and beneficial owners of more than 10% of a class of stock. So a CEO, CFO, a board member, or a large activist fund all file Form 4s when their holdings change.

The two tables

A Form 4 has two parts that matter:

Table I — Non-derivative securities. This is common stock: the shares themselves. An open-market purchase of common stock shows up here.
Table II — Derivative securities. Options, warrants, and convertibles. A "purchase" reported here is often a compensation award (e.g., warrants from an employment agreement), not cash conviction — a crucial distinction.

The fields that matter

Transaction code — a letter (P, S, A, M, F…) describing the type of trade. "P" is an open-market purchase. (See our guide to Form 4 codes.)
Acquired (A) or Disposed (D) — whether shares went up or down.
Amount, price, and date — how many shares, at what price, when.
Footnotes — easy to skip, but they often reveal that a "purchase" is actually a grant, or that the buy was under a pre-set plan.

Telling a real buy from noise

A high-conviction signal is an open-market purchase of common stock (code P), with real dollars, by a senior insider, with no offsetting sale. A low-information event is a compensation award (code A), an option exercise (M), or a sale to cover taxes (F). The footnotes are where the truth usually hides — always read them.

Built for exactly this

Reading every Form 4 across thousands of companies isn't realistic manually. ClearOcean parses them all, flags genuine open-market buys, and skips grants, exercises and tax sales for you.

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Frequently asked

What is an SEC Form 4?

A Form 4 is the filing corporate insiders must submit to the SEC, generally within two business days, to disclose changes in their ownership of the company's stock.

Where can I find Form 4 filings?

All Form 4s are public and free on the SEC's EDGAR database. You can search by company ticker or by the insider's name.

Sources

U.S. Securities and Exchange Commission — EDGAR full-text search and Form 4 documentation.

Keep reading

This guide is educational and informational only — not investment, legal or tax advice, and not a recommendation to buy or sell any security. ClearOcean is a software research service, not a registered investment adviser or broker-dealer. Investing involves risk, including the total loss of capital. Consult a licensed professional.