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What Is SEC Form 4? Insider Trading Filings Explained
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What Is SEC Form 4? Insider Trading Filings Explained

Form 4 is the public record of a company insider buying, selling or otherwise changing a stake. Here is who files it, when, and what it can and cannot tell you.

GUIDE · PUBLISHED 2026-10-12 · UPDATED 2026-10-12

General information about public filing rules, not legal or investment advice. Check the primary sources below before relying on any detail.

What Form 4 is

Form 4 is titled "Statement of Changes in Beneficial Ownership of Securities". It is filed under Section 16(a) of the Securities Exchange Act of 1934, and it reports a change in how many shares, options or other equity securities of a company an insider owns. Each Form 4 covers one company: an insider who sits on two boards files separately for each.

Form 4 is one of three related forms. Form 3 is the initial statement of holdings, filed when a person first becomes an insider. Form 4 reports changes as they happen. Form 5 is an annual statement, due within 45 days after the company's fiscal year end, for certain transactions that did not have to be reported on Form 4 earlier. On WaveMan, Form 4 is the filing behind insider buying, insider selling and the insider section of every company page, such as Apple.

Who has to file Form 4

Section 16(a) covers three groups for a company with a class of equity securities registered under the Exchange Act:

  • Directors of the company.
  • Officers of the company.
  • Beneficial owners of more than 10 percent of any class of the company's registered equity securities.

The statute also requires an initial statement within 10 days after a person becomes a director, officer or more than 10 percent owner. A person who is not a director, officer or 10 percent holder but still reports checks "other" on the form and explains why. The form also has a box to tick when the person is no longer subject to Section 16, with a reminder that reporting obligations can continue for a time after that.

The deadline: two business days

Form 4 must be filed before the end of the second business day following the day on which the transaction was executed. That timing is written into the statute itself, Section 16(a)(2)(C), and repeated in Rule 16a-3(g) and in the form's General Instructions. A trade executed on a Monday is therefore due by the end of Wednesday, absent a holiday.

There is one nuance worth knowing. For a trade under a qualifying Rule 10b5-1 plan, or a discretionary transaction under an employee plan, where the insider did not pick the date, Rule 16a-3(g) treats the execution date as the day the broker or plan administrator notifies the insider, but no later than the third business day after the trade. The clock then runs from that deemed date.

Form 4 is filed electronically on EDGAR, and the statute requires the SEC to post it, and a company with a corporate website to post it there, by the end of the business day after filing. That is why Form 4 is one of the fastest public signals of insider activity: today's insider buying is usually a day or two behind the trades.

What the form shows

A Form 4 has two tables:

  • Table I lists non-derivative securities acquired, disposed of or beneficially owned, usually common stock.
  • Table II lists derivative securities, such as options, warrants and convertible securities.

Each row carries the transaction date, a one-letter transaction code, the number of shares, whether they were acquired (A) or disposed of (D), the price, the amount owned after the transaction, and whether ownership is direct or indirect (for example through a trust or a family member). Each transaction goes on its own line, and footnotes in the explanation of responses cover anything the columns cannot. A code J row, for example, must be described there.

Transaction codes

The code tells you what kind of transaction it was. Code P is an open market or private purchase, and code S is an open market or private sale. Code A is a grant or award under Rule 16b-3, code M is an option exercise or conversion exempted under Rule 16b-3, code F is shares withheld or delivered to pay an exercise price or a tax bill, and code G is a bona fide gift. The full list, with what each code does and does not mean, is in our guide to Form 4 transaction codes.

The Rule 10b5-1 checkbox

Rule 10b5-1 gives an affirmative defense against insider trading liability to a person who trades under a contract, instruction or written plan adopted before they had material nonpublic information. The SEC amended the rule in December 2022, effective February 27, 2023, and the amendments added a Form 4 checkbox. The form now asks the filer to indicate whether a transaction was made under a plan intended to satisfy the Rule 10b5-1(c) defense, and to give the date the plan was adopted in the explanation of responses.

The same amendments set cooling-off periods. A director or officer cannot trade under a new or modified plan until the later of 90 days after adoption or two business days after the company discloses its financial results for the quarter in which the plan was adopted, capped at 120 days. For other persons, other than the company itself, the cooling-off period is 30 days. A sale under a plan was scheduled in advance, which is why it usually says less about the insider's current view than a sale outside a plan.

How to read a Form 4 without overreading it

  • Check the code first. Most Form 4 rows are not trades at all. Grants (A), exercises (M) and tax withholding (F) are compensation mechanics, not decisions to buy or sell.
  • Check the 10b5-1 box. A planned sale was set up months earlier.
  • Check direct or indirect. Indirect holdings may belong to a trust or a family member.
  • Remember purchases are rare. Insiders receive stock as pay, so selling is routine and buying with their own money is the less common event.
  • Do not treat a purchase as a forecast. Our own study of every insider purchase since 2021 found that buying alongside insiders did not beat the market on average.

Form 4 is often read together with Form 144, the notice some insiders file before a sale, which WaveMan lists as planned sales.

Frequently asked questions

What is the deadline for filing Form 4?

Form 4 must be filed before the end of the second business day following the day the transaction was executed. For some plan trades where the insider did not choose the date, the execution date is deemed to be the day the insider is notified, but no later than the third business day after the trade.

Who has to file Form 4?

Directors and officers of a company with a class of equity securities registered under the Exchange Act, and beneficial owners of more than 10 percent of any class of its registered equity securities.

What is the difference between Form 3, Form 4 and Form 5?

Form 3 is the initial statement of holdings when someone becomes an insider. Form 4 reports changes in ownership within two business days. Form 5 is an annual statement, due within 45 days after the company's fiscal year end, for certain transactions not already reported on Form 4.

What does the 10b5-1 checkbox on Form 4 mean?

It indicates that the transaction was made under a contract, instruction or written plan intended to satisfy the affirmative defense in Rule 10b5-1(c). The filer is asked to give the plan's adoption date. The checkbox came with SEC amendments effective February 27, 2023.

Sources

Every rule, deadline and threshold above was checked against these primary documents on 2026-10-12:

More guides

Source: U.S. Securities and Exchange Commission (EDGAR) and other official government data · Updated 2026-10-12 · For informational purposes only, not investment advice.
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