Who has to file a Form 4?

Section 16 reporting persons — a company's officers, directors, and beneficial owners of more than 10% of its stock — must file a Form 4 for any change in their ownership of the company's securities.

How quickly must a Form 4 be filed?

Within two business days of the transaction that changed the insider's ownership.

Does an insider sale on a Form 4 signal that the stock will fall?

Not necessarily. A sale (transaction code S) is often routine — for diversification, taxes, or under a pre-arranged 10b5-1 plan. Check whether the 10b5-1 box is checked before drawing conclusions. An open-market purchase (code P) is generally read as the stronger insider signal.

What is a Rule 10b5-1 trading plan?

A written trading plan an insider pre-establishes during an open window. Trades executed under the plan are protected from insider-trading liability even if they occur during an otherwise-closed window — which is why a sale under a 10b5-1 plan carries less signal than a discretionary one.

Learn / form-4

What is a Form 4 filing?

Form 4 is the SEC insider-transaction report. Officers, directors, and ≥10% beneficial owners (Section 16 reporting persons) must file within two business days of any change in their ownership of the company's securities.

Last updated: 2026-07-30. Source: SEC EDGAR.

Who files a Form 4 — Section 16 reporting persons

Section 16 of the Securities Exchange Act of 1934 identifies three categories of insider:

Officers of the issuer (executive officers per the company's Section 16 designation).
Directors of the issuer.
≥10% beneficial owners of any registered class of equity securities.

These three categories are required to disclose their holdings via Form 3 (initial), Form 4 (changes), and Form 5 (annual catch-up).

The two-business-day rule

Form 4 must be filed within two business days of the transaction date. This was tightened from 10 days by Sarbanes-Oxley (2002). The short window means insider transactions are nearly contemporaneous public information.

A few exceptions exist (e.g., certain pre-arranged Rule 10b5-1 trading plans, transactions with the issuer that may delay reporting), but for most market-relevant transactions, the disclosure is fast.

How to read a Form 4 — Tables I and II

Form 4 has two transaction tables:

Table I — Non-Derivative: ordinary common-stock transactions. The columns most observers track: Transaction Date, Transaction Code (P = open-market purchase, S = open-market sale, A = grant, M = exercise, D = disposition), Amount, Price, Acquired/Disposed code (A/D).
Table II — Derivative: options, warrants, RSUs, and other derivative securities. Often where compensation grants and exercises live.

The transaction code matters more than the column header. Code P (open-market purchase using personal funds) is the strongest insider signal. Code S (open-market sale) is noisier — many insider sales are routine 10b5-1 plan executions or tax-related, not bearish bets.

10b5-1 trading plans

Rule 10b5-1 lets insiders pre-schedule trades during open windows so the actual execution can occur during a closed window without violating insider-trading rules. Form 4 disclosures include a checkbox indicating whether the transaction was pursuant to a 10b5-1 plan (since 2023). A checked box reduces the signal value of the trade — the decision was made months ago, not in response to current information.

Frequently asked questions

Who has to file a Form 4?: Section 16 reporting persons — a company's officers, directors, and beneficial owners of more than 10% of its stock — must file a Form 4 for any change in their ownership of the company's securities.
How quickly must a Form 4 be filed?: Within two business days of the transaction that changed the insider's ownership.
Does an insider sale on a Form 4 signal that the stock will fall?: Not necessarily. A sale (transaction code S) is often routine — for diversification, taxes, or under a pre-arranged 10b5-1 plan. Check whether the 10b5-1 box is checked before drawing conclusions. An open-market purchase (code P) is generally read as the stronger insider signal.
What is a Rule 10b5-1 trading plan?: A written trading plan an insider pre-establishes during an open window. Trades executed under the plan are protected from insider-trading liability even if they occur during an otherwise-closed window — which is why a sale under a 10b5-1 plan carries less signal than a discretionary one.

Our view

Insider buying is a stronger signal than insider selling. Officers and directors sell for a hundred reasons (taxes, diversification, scheduled plans, life events). They buy for one: they think the stock is mispriced. Cluster Form 4 buys — multiple unrelated insiders buying within a short window — are among the highest-conviction qualitative signals on EDGAR.

See live data

Browse live Form 4 filings — 15 filings indexed. Updated as new EDGAR submissions are ingested.

Sister-property applied analysis

SecFilingDex catalogs the filings. For applied analysis on the same SEC corpus — narrowed to tracked superinvestors with framework + POV — see the sister site:

HoldLens: Form 4 vs 13F (the comparison) — When does each filing actually matter? The two-day Form 4 disclosure vs the 45-day-stale 13F snapshot — read together they answer different questions.
HoldLens: Live insider tracker (InsiderScore) — Scored Form 4 activity across major tickers — clustered insider buying/selling signals, not just the raw filings.
HoldLens: How InsiderScore is computed — Methodology for turning Form 4 transactions into a scored signal — what gets weighted, what gets ignored, why.

Reading on filings

Understanding the form is step one; reading one is step two. These are the references that help with the second part.

Security Analysis — Benjamin Graham & David Dodd
The reference on reading a filing and valuing what is inside it. Dense, and still the book the rest cite.
Financial Shenanigans — Howard M. Schilit
How accounting manipulation actually shows up in disclosures — written around real filings and what gave them away.
Financial Statement Analysis — Martin S. Fridson & Fernando Alvarez
A working guide to the statements inside a 10-K or 20-F, including where the notes matter more than the headline numbers.
The Intelligent Investor — Benjamin Graham
The plain-language starting point if the filings are new to you and the vocabulary is the obstacle.
The Essays of Warren Buffett — Lawrence A. Cunningham (ed.)
Shareholder letters organised by theme — a filer's own account of what disclosure is for, from the reporting side.

Several of these are on Audible — free trial — Graham and Fridson both read well as audio if you are commuting.

Book links go to Amazon. As an Amazon Associate, SecFilingDex earns from qualifying purchases, at no extra cost to you. The filings data on this site is free and never changes based on these links.

Glossary

Form 4: SEC report under Section 16 disclosing changes in beneficial ownership of issuer securities by officers, directors, and ≥10% beneficial owners. Must be filed within two business days of the transaction.
Section 16: Section 16 of the Securities Exchange Act of 1934. Establishes the reporting and trading restrictions for officers, directors, and ≥10% beneficial owners of public companies.
Rule 10b5-1: SEC rule allowing insiders to pre-establish written trading plans during open windows; trades executed under the plan are protected from insider-trading liability even if executed during closed windows.
Transaction Code P: Form 4 transaction code indicating an open-market or private purchase of securities. Generally interpreted as the strongest insider signal.
Transaction Code S: Form 4 transaction code indicating an open-market or private sale of securities. Often routine; check whether 10b5-1 box is checked before drawing conclusions.