Form 3 vs Form 4 vs Form 5
Section 16 uses three forms, and they answer three different questions: what do you own when you arrive (Form 3), what did you just trade (Form 4), and what did the year miss (Form 5). All three flow through the same feeds on this site, labelled by form type on every row.
| Form | When it’s filed | Deadline | What it reports |
|---|---|---|---|
| Form 3 | Once, on becoming a director, officer or 10% owner | Within 10 days (before effectiveness at an IPO) | A snapshot of everything already owned — even if that is nothing |
| Form 4 | Every time ownership changes | End of the second business day after the trade | The transaction: shares, price, code, and holdings after |
| Form 5 | Annually, if anything is left to report | 45 days after the company’s fiscal year end | Exempt small acquisitions and anything a Form 4 missed |
Form 3 — the starting balance
Filed once per insider per company, within ten days of getting the role (or by the time the registration statement goes effective when a company lists). It reports holdings, not trades — so a Form 3 never appears in a buy or sale feed here, but it seeds each company’s insider-holders page with a first balance (every company page links to its holders). A Form 3 is required even when the new insider owns no shares at all.
Form 4 — the transaction report
The workhorse: nearly all of the volume, and everything people mean when they talk about “insider trading data.” Two business days from trade to public record, every line carrying a transaction code that says what kind of event it was. The Form 4 guide covers it in full.
Form 5 — the annual sweep
Due within 45 days of fiscal year end, and only if there is something to put on it: transactions exempt from Form 4 reporting (like small acquisitions under Rule 16a-6) and anything that should have been on a Form 4 during the year but wasn’t — Form 5 doubles as the confession form for missed filings. Historically, gifts of stock rode on Form 5 too; since the SEC’s 2023 amendments, gifts must be reported on Form 4 within two business days, which has made Form 5s rarer. Many insiders never need to file one.
Amendments
Any of the three can be amended — the form type gains a “/A” (4/A, 3/A, 5/A). An amendment supersedes the original for the same period. This site keeps both, marks the original as amended, and never overwrites: the version chain is part of the record.
Common questions
Does a Form 3 mean an insider bought stock?
No. Form 3 is an initial snapshot of holdings filed when someone becomes an insider. No transaction happened — the shares reported may have been owned for years before the person became subject to Section 16.
Why would an insider file a Form 5 instead of a Form 4?
Only for transactions exempt from Form 4’s two-day rule, such as small acquisitions under Rule 16a-6, or to report a transaction that was missed during the year. Anything eligible for Form 4 reporting can also be reported early on a Form 4 voluntarily, which is why Form 5s are uncommon.
Which forms show up in insider buy/sell feeds?
Effectively only Form 4 (and its amendments). Form 3 reports holdings rather than trades, and Form 5 mostly carries exempt or catch-up items. This site parses all three, and open-market purchases and sales — wherever reported — are what land in the buy and sale feeds.
Keep reading
- What is SEC Form 4? — SEC Form 4 explained: who must file it, the two-business-day deadline, what Tables I and II report, and how insider buys and sales become public record.
- How to read a Form 4 — A walkthrough of a Form 4 insider filing: the relationship boxes, every Table I and Table II column, the footnotes, and the Rule 10b5-1 checkbox.
- Form 4 filing deadlines — When a Form 4 is due: the two-business-day rule from Sarbanes-Oxley, EDGAR’s 10 pm cutoff, the narrow exceptions, and what actually happens to late filers.
- Transaction codes — What each SEC Form 4 transaction code means — P, S, A, M, F, G and the rest — and which ones are real open-market trades.
- Rule 10b5-1 trading plans — What a Rule 10b5-1 trading plan is, the 2023 cooling-off and disclosure amendments, the Form 4 checkbox, and how to read planned versus discretionary trades.
- What is insider trading? — Insider trading is legal when insiders report their trades and illegal when anyone trades on material non-public information.
- Reading insider buying — Which insider-buying patterns carry information according to the published research — cluster buys, purchase size versus stake, the buyer’s role — and which are noise.