How to read a Form 4

A Form 4 is four questions in a fixed layout: who traded, what their relationship to the company is, what exactly happened, and what they hold now. Read in that order, every filing takes under a minute. Open any filing from the buy feed and follow along — this site renders them in the SEC’s own layout.

1. The header: who, and in what capacity

The top of the form names the reporting person, the company (the “issuer”), and the relationship checkboxes: director, officer (with a title), 10% owner, other. The relationship is context for everything below — a CFO’s open-market buy reads differently from a fund crossing a reporting threshold. Watch for filings with several reporting owners: trusts and funds often file jointly with their managers, which is bookkeeping, not three people buying.

2. Table I: non-derivative transactions

Each line is one transaction in the company’s stock. The columns that matter:

Transaction code — a single letter that says what kind of event this was. P is an open-market purchase, S an open-market sale, and nearly everything else is compensation mechanics or transfers. The code reference covers all nineteen.
Amount and price — shares and the price per share. A price of $0 on a “sale” line is the tell that it is not really a sale: gifts, transfers into trusts and plan events wear trade codes with zero prices. This site never counts those as trades.
(A) or (D) — acquired or disposed. Combined with the code, this is the direction of the transaction.
Shares owned following transaction — the running balance. Divide the trade size by this to get the number that matters most: how much of their stake did they move? Selling 5,000 shares means one thing from a 6,000-share position and another from a 2 million-share one — the Δ-stake column in the feeds here does this arithmetic for you.
Direct or indirect (D/I) — indirect holdings are through trusts, LLCs, family members or retirement plans, with the vehicle named in the “nature of ownership” column and usually a footnote.

3. Table II: derivatives

Options, RSUs, warrants and convertible notes live here, each with a conversion or exercise price, an exercisable date and an expiration date. The common pattern to recognize is M then S: an option exercised in Table II, the resulting shares sold in Table I, often the same day. That is compensation being cashed out on schedule — very different from an unprompted open-market purchase.

4. Footnotes and the 10b5-1 checkbox

The numbered footnotes are where filers explain themselves: weighted-average prices with the actual range, trust structures, plan details. Never skip them on a filing you care about. And since 2023, a checkbox states whether the trade was executed under a Rule 10b5-1 plan adopted earlier — checked means the timing was pre-scheduled, which drains most of the signal from a sale. On older filings the checkbox simply didn’t exist; this site shows those as “unknown” rather than pretending the answer is no.

The thirty-second read

Relationship: who is this, at which company?
Codes: any P or priced S lines, or is it all plumbing?
Size against the owned-after balance: does the trade move their stake?
10b5-1 box and footnotes: was the timing theirs, and what’s the fine print?

Common questions

What does transaction code P mean on a Form 4?

An open-market or private purchase of securities — the insider spending their own money on the stock. It is the single most watched code because it is voluntary, unlike grants, vestings and tax withholdings.

Why do some Form 4 sales show a price of zero?

Because they are not market sales: gifts, transfers to trusts, and certain plan events are reported with trade-like codes but no price. A $0 “sale” of millions of shares is a transfer wearing a sale’s clothing, and a careful reader — or a careful site — treats it as such.

What does “indirect ownership” mean on a Form 4?

The shares are held through another vehicle the insider controls or benefits from — a family trust, an LLC, a spouse, a 401(k). The “nature of ownership” column names the vehicle, and footnotes usually give detail.

What is the difference between the transaction date and the filing date?

The transaction date is when the trade executed; the filing date is when the report reached the SEC. They are at most two business days apart when the filer is on time — this site flags filings that arrive later than that.

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.
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.
Form 3 vs Form 4 vs Form 5 — The three Section 16 ownership forms compared: Form 3 when you become an insider, Form 4 within two business days of a trade, Form 5 as the annual catch-up.
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.