Form 4

The SEC filing an officer, director or ten-per-cent holder makes when their own holding in the company changes, due before the end of the second business day after the transaction. It is the fastest record in the US disclosure system and the most over-read: the form states what moved, how many shares and at what price, and it says almost nothing about why.

How it works

Section 16 of the Exchange Act makes officers, directors and holders of more than ten per cent of a registered class report their own transactions in the company's stock. Form 4 is the report for a change in holdings, and its deadline is unusually tight: before the end of the second business day after the transaction was executed. That came from the Sarbanes-Oxley Act in 2002, which rewrote section 16(a), and it sits in Rule 16a-3 today. It is statutory rather than an SEC scheduling preference, which is why no amount of lobbying has widened it and why this is the freshest disclosure in the American record — days, not the quarters a 13F runs on.

There is one exception worth knowing, because it explains filings that look late and are not. Where the transaction ran under a pre-arranged arrangement and the insider did not pick the execution date, the two days can run from the broker's notification instead, capped at the third business day after the trade. Worst case, a fully compliant Form 4 arrives five business days out.

The form itself has two tables. The first covers non-derivative securities — ordinary shares held. The second covers derivatives: options, warrants, restricted stock units, convertibles. Every row carries a transaction code, and the codes are the part that decides what the filing means.

Direction is the least informative field on it

This is the trap, and it is the whole reason the term needs a page.

An insider "buy" is frequently not a purchase. An increase in shares held can be an open-market buy at market prices with the insider's own money, or the exercise of an option granted years earlier at a strike set then, or an award vesting on a schedule agreed before anyone knew where the price would be. All three raise the holding. Only the first is a decision about today's price. The code on the row tells them apart; a screener that renders every one of them as a green arrow does not.

An insider "sale" is frequently automatic. Since the SEC's 2022 amendments, Form 4 carries a mandatory checkbox indicating whether the transaction was made under a Rule 10b5-1(c) arrangement — a plan adopted in advance, often months before, by someone who did not choose the week it executed. The box has been required on reports filed since 1 April 2023, so any time series spanning that date changes shape partway through. Sales to cover the tax on vesting shares are in the same family: they are an administrative consequence of compensation, not a view.

Form 5 is where the misses land. Transactions that should have been reported during the year but were not get swept onto Form 5, due 45 days after the issuer's fiscal year end. A trade can therefore become public more than a year later, on a form most trackers treat as an afterthought, and a late-filed Form 4 breaks up any clean count of filings per month.

Why it matters here

Two fields decide whether a tracker in this category is worth paying for: the transaction code, and the 10b5-1 box. A product that exposes both lets you separate discretionary trades from plumbing. A product that shows a name, a ticker, a direction and a dollar amount has performed a lossy compression on the filing and cannot be un-compressed.

OpenInsider is free, minutes behind EDGAR and the best filter in the category, and it is also one of the tools that does not surface the 10b5-1 box — worth knowing rather than disqualifying, because the underlying filing does carry it. SECForm4 and Insider Screener take the screening further, the latter across seventeen markets, and 2iQ Insider Data sells the international version of the same object. SEC EDGAR is the filing itself, free and structured, and how to get SEC filings as data is the route in. For where this sits among the other disclosure clocks, see when a trade shows up in the public record.

Where you will meet this

The cards where this changes a decision, then the rest that use the word.

Sources

  1. Sarbanes-Oxley Act of 2002, Public Law 107-204, section 403 — U.S. Government Publishing Office, . The two-business-day deadline it wrote into Exchange Act section 16(a)(2)(C) is restated word for word in Rule 16a-3(g)(1) today.
  2. 17 CFR 240.16a-3 — Reporting transactions and holdings — Office of the Federal Register, read
  3. Insider Trading Arrangements and Related Disclosures, Final Rule (87 FR 80362) — Securities and Exchange Commission, . The checkbox it made mandatory on Forms 4 and 5 has applied to Section 16 reports filed since 1 April 2023 and stands in the rule as amended.
  4. Form 4: Statement of Changes in Beneficial Ownership — U.S. Securities and Exchange Commission, read

FAQ

Does an insider buy mean the insider thinks the stock is cheap?

Sometimes, and the form will not tell you which times. An increase in holdings can be an open-market purchase made with the insider's own money, or the exercise of an option granted years ago, or shares vesting under a plan nobody chose the date of. The transaction code on the row separates them, and a tracker that shows only a direction has thrown that away.

How late can a Form 4 legitimately be?

Five business days, in one specific case. Where a transaction ran under a pre-arranged plan and the insider did not select the execution date, the clock can start when the broker gives notice, capped at the third business day after the trade. Beyond that a transaction missed during the year is swept onto Form 5, which is not due until 45 days after the fiscal year ends.

Updated