# Form 4

> The SEC filing that reports a change in an insider's holdings, such as a purchase, sale, option exercise or grant, generally within two business days.

Source: https://www.quantisnow.com/glossary/form-4
Topic: Glossary / Insiders and ownership
Also known as: SEC Form 4, statement of changes in beneficial ownership, Form 4 filing
Last updated: 2026-10-27

Form 4 is the statement of changes in beneficial ownership that officers, directors and more-than-10% holders must file with the SEC when they buy, sell or otherwise change their holdings of a company's equity. Most transactions must be reported before the end of the second business day after the trade.

## How it works

Form 4 has two tables. Table I covers common stock; Table II covers derivatives such as options, warrants and convertible securities. Each line carries a transaction code. The ones traders watch most:

| Code | Meaning |
| --- | --- |
| P | Open-market or private purchase |
| S | Open-market or private sale |
| A | Grant or award from the company |
| M | Exercise or conversion of a derivative |
| F | Shares withheld to pay exercise price or taxes |
| G | Gift |

Footnotes explain the details, including whether a sale was made under a [Rule 10b5-1 trading plan](https://www.quantisnow.com/glossary/rule-10b5-1-plan). Since 2023 the form has a checkbox for trades under such plans.

## Why it matters for traders

Code P is the signal most investors look for: an insider spending personal cash on shares at market prices. [Insider buying](https://www.quantisnow.com/glossary/insider-buying) by several insiders in a short window (a "cluster buy") tends to draw more attention than a single purchase. Sales are noisier, since insiders sell for taxes, diversification and pre-scheduled plans. Codes A, M and F are usually compensation mechanics and carry little information.

Check the size relative to the insider's existing stake and salary, the price paid, and whether the trade came soon after an earnings release, when trading windows typically open.

## Example

The CEO of Harbor Freightline (ticker HRBF) buys 40,000 shares at $12.50 on Monday, a $500,000 purchase. The Form 4 is due by Wednesday. It shows code P, a price of $12.50 and holdings after the trade of 640,000 shares, meaning the purchase raised her stake by about 6.7%.

## FAQ

### How long do insiders have to file a Form 4?

Generally two business days after the transaction. Certain small or exempt transactions can be deferred to Form 5.

### Does every Form 4 mean an insider bought or sold on the market?

No. Many Form 4s report grants, option exercises, tax withholding or gifts. Look at the transaction code.

## Related terms

- [Form 3](https://www.quantisnow.com/glossary/form-3.md): The initial SEC statement of beneficial ownership filed by a company's officers, directors and 10% holders when they first become insiders.
- [Form 5](https://www.quantisnow.com/glossary/form-5.md): An annual SEC filing where insiders report exempt or small transactions that were not already disclosed on Form 4, due 45 days after fiscal year end.
- [Insider buying](https://www.quantisnow.com/glossary/insider-buying.md): Purchases of a company's stock by its officers, directors or 10% holders, reported to the SEC on Form 4 and watched as a signal of insider confidence.
- [Rule 10b5-1 trading plan](https://www.quantisnow.com/glossary/rule-10b5-1-plan.md): A prearranged written plan that lets insiders buy or sell stock on a set schedule, providing an affirmative defense against insider trading claims.
- [Form 144](https://www.quantisnow.com/glossary/form-144.md): A notice filed with the SEC when an affiliate or holder of restricted stock plans to sell shares under Rule 144 above set size thresholds.
- [Beneficial owner](https://www.quantisnow.com/glossary/beneficial-owner.md): A person who has or shares voting or investment power over a security, directly or indirectly, even if the shares are held in another name.

## On Quantisnow

- [Form 4 explained](https://www.quantisnow.com/guides/form-4-insider-trading-explained)
- [SEC Form 4 insider transactions](https://www.quantisnow.com/categories/form-4)
- [Live feed: Insider Trading](https://www.quantisnow.com/news/insider-trading)
- [Insider trading tracker](https://www.quantisnow.com/insiders)
- [Latest insider purchases](https://www.quantisnow.com/top/insider-purchases)