# Form 3

> The initial SEC statement of beneficial ownership filed by a company's officers, directors and 10% holders when they first become insiders.

Source: https://www.quantisnow.com/glossary/form-3
Topic: Glossary / Insiders and ownership
Also known as: SEC Form 3, initial statement of beneficial ownership
Last updated: 2026-10-27

Form 3 is the initial statement of beneficial ownership that an officer, director or holder of more than 10% of a registered class of equity securities must file with the SEC under Section 16(a) of the Securities Exchange Act. It establishes the baseline holdings that every later [Form 4](https://www.quantisnow.com/glossary/form-4) and [Form 5](https://www.quantisnow.com/glossary/form-5) is measured against.

## How it works

- **Who files:** anyone who becomes a Section 16 insider: executive officers, directors, and [beneficial owners](https://www.quantisnow.com/glossary/beneficial-owner) of more than 10% of a class of registered equity.
- **Deadline:** within 10 days of becoming an insider. For a company going public, insiders file by the effective date of the registration statement.
- **What it lists:** every equity security the insider beneficially owns at that moment, including common stock, options, warrants, RSUs and convertible securities, plus whether ownership is direct or indirect (through a trust, LLC or family member).
- **Even if empty:** a new director who owns zero shares still files a Form 3 showing no holdings.

Form 3 is filed electronically on [EDGAR](https://www.quantisnow.com/glossary/edgar) and is public immediately.

## Why it matters for traders

A Form 3 is rarely a price catalyst by itself, but it is a useful signal of change. A cluster of Form 3 filings often marks a new management team, a board refresh after an activist settlement, or an investor crossing 10% ownership. That last case is worth reading closely: a fund that files a Form 3 because it now owns more than 10% becomes subject to short-swing profit rules and must report every subsequent trade on Form 4.

## Example

Northwind Therapeutics (ticker NWTX) appoints a new chief financial officer effective March 3. She holds 12,000 NWTX shares from a prior advisory role and receives a grant of 150,000 stock options on her start date. Her Form 3, due by March 13, shows 12,000 shares held directly and, depending on timing, the option grant (which may instead be reported on a Form 4).

## FAQ

### What is the difference between Form 3 and Form 4?

Form 3 is a one-time snapshot filed when someone becomes an insider. Form 4 reports each later change in holdings, generally within two business days of the transaction.

### Does a 10% shareholder file Form 3?

Yes. Anyone who becomes the beneficial owner of more than 10% of a registered class of equity securities must file a Form 3 within 10 days.

## Related terms

- [Form 4](https://www.quantisnow.com/glossary/form-4.md): 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.
- [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.
- [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.
- [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.
- [EDGAR](https://www.quantisnow.com/glossary/edgar.md): The SEC's electronic system where public companies, insiders and funds submit filings and where anyone can read them for free.

## On Quantisnow

- [SEC Form 3 initial insider statements](https://www.quantisnow.com/categories/form-3)
- [Form 4 explained](https://www.quantisnow.com/guides/form-4-insider-trading-explained)
- [Insider trading tracker](https://www.quantisnow.com/insiders)
- [Live feed: Insider Trading](https://www.quantisnow.com/news/insider-trading)