# What Is Insider Selling? Definition and Example

> Insider selling is when executives, directors or big shareholders sell their own company’s stock. Here is how it is reported, what research found, and how to tell routine sales from meaningful ones.

Source: https://www.exent.ai/learn/insider-selling · Reviewed by David, Senior Analyst, Exent · Published Nov 3, 2026 · Updated Nov 3, 2026

## Key takeaways

- Insider selling is the sale of a company’s stock by its officers, directors or holders of more than 10% of its shares; in the US it must be reported to the SEC on Form 4 within two business days.
- Lakonishok and Lee (2001), studying 1975–1995, found insider purchases predicted returns while insider sales showed little predictive power.
- Many sales are routine: diversification, taxes or pre-set Rule 10b5-1 plans, which since the SEC’s December 2022 amendments carry a cooling-off period of at least 90 days for directors and officers.
- Clusters of unplanned sales by several insiders get more attention than one scheduled sale.

## What is insider selling?

Insider selling is legal selling by people with privileged access to a company: officers, directors and owners of more than 10% of its stock. Each trade is disclosed on [Form 4](https://www.exent.ai/learn/form-4), due by the end of the second business day after the trade, according to the [SEC](https://www.investor.gov/news-alerts/investor-bulletins/investor-bulletin-insider-transactions-forms-3-4-5).

## Why do insiders sell?

Executives are often paid largely in stock, so selling is how they diversify, pay taxes or buy a house. Many sell through Rule 10b5‑1 plans set up in advance; the [SEC’s December 2022 rules](https://www.sec.gov/news/press-release/2022-222) added a cooling‑off period before such plans can trade. Buying is different: there is mainly one reason to buy.

## Example: routine vs unusual selling

| Pattern | What the filings show | How investors usually read it |
| --- | --- | --- |
| Routine | CEO sells 3% of holdings monthly under a 10b5-1 plan | Low signal |
| Unusual | CFO and two directors sell 40% of holdings on the open market in one week | Worth a closer look |

*Illustrative.* Research by [Lakonishok and Lee (2001)](https://ideas.repec.org/a/oup/rfinst/v14y2001i1p79-111.html) found the information in insider trades came mostly from purchases, which is why [insider buying](https://www.exent.ai/learn/insider-buying) gets more weight.

## Why it matters for a self‑directed investor

Headlines about “insiders dumping shares” are common and usually overstate the signal. Context matters: the share of holdings sold, whether a plan was in place, and how many insiders acted. See also [how to track smart money](https://www.exent.ai/resources/how-to-track-smart-money).

## Common mistakes

- Treating every insider sale as a warning.
- Ignoring whether the sale was under a pre-set 10b5-1 plan.
- Looking at dollar amounts instead of the share of the insider’s holdings.
- Missing option exercises, where shares are sold to cover the exercise cost or taxes.

## See insider selling in context with Exent

1. Open a stock in Stocks Radar to see insider activity next to analyst ratings and 13F views.
2. Portfolio Analysis shows analyst and insider activity on the holdings you upload.

Exent is our product: [Exent Gems](https://www.exent.ai/radar)

## Frequently asked questions

### Is insider selling a bad sign?

Usually not on its own. Research has found insider sales carry little predictive information on average, because insiders sell for many personal reasons.

### How quickly must insider sales be reported?

In the US, officers, directors and 10% holders must file Form 4 with the SEC by the end of the second business day after the trade.

### What is a 10b5-1 plan?

A pre-arranged trading plan that lets insiders sell on a set schedule. Since the SEC’s 2022 amendments, directors and officers must wait at least 90 days after adopting one before trades begin.

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Educational content, not investment advice. Past performance does not guarantee future results.