What is SEC Form 4?
The disclosure that turns insider trading into public, researchable data.
The filing
Form 4 is the statement of changes in beneficial ownership that corporate insiders — officers, directors, and owners of more than ten percent of a registered class of equity — must file with the U.S. Securities and Exchange Commission. Each filing reports what an insider bought, sold, received, or exercised, at what price, and how much they still hold afterwards.
Who files, and when
Reporting is done by the insider, not by the company. Most transactions must be reported within two business days after they occur. The timestamp that matters for research is not the trade date but the moment the filing becomes publicly available on SEC EDGAR — before that moment, the information was not public and must not be treated as knowable.
The fields that matter
A Form 4 carries the issuer and its ticker, the reporting owner and their role, the transaction date, a transaction code, the amount of securities, the price per share, and the ownership after the transaction. InsiderAlpha normalizes these fields so that millions of filings become one consistent, queryable event stream.
Reading transaction codes
Transaction code P marks an open-market purchase — an insider spending their own money. Code S marks an open-market sale. Codes such as A (grants) or M (option exercises) describe compensation-driven changes that carry a different meaning than open-market trades. Research should separate these categories instead of treating every insider transaction as one signal.
What it can and cannot tell you
A purchase tells you that an insider chose to increase exposure with personal funds, publicly and on the record. It does not tell you why, and it is never, on its own, a promise of future returns. InsiderAlpha treats every reading of Form 4 data as a candidate signal — a hypothesis for research, not a recommendation to trade.
Common transaction codes
- POpen-market purchase
- SOpen-market sale
- AGrant or award
- MOption exercise