# Dilution

> The reduction in existing shareholders' ownership percentage and per-share claims on earnings when a company issues new shares.

Source: https://www.quantisnow.com/glossary/dilution
Topic: Glossary / IPOs and offerings
Also known as: share dilution, stock dilution, equity dilution, dilutive offering
Last updated: 2026-10-27

Dilution is the decrease in an existing shareholder's percentage ownership of a company, and in their claim on its earnings and assets per share, that occurs when the company issues additional shares. The investor holds the same number of shares, but each share represents a smaller slice of the company.

## How it works

Common sources of dilution include:

- Equity offerings: [follow-ons](https://www.quantisnow.com/glossary/follow-on-offering), [ATM programs](https://www.quantisnow.com/glossary/at-the-market-offering), registered directs and PIPEs
- Exercise of [warrants](https://www.quantisnow.com/glossary/warrants) and employee stock options
- Conversion of [convertible notes](https://www.quantisnow.com/glossary/convertible-notes) or preferred stock
- Stock-based compensation and restricted stock vesting
- Stock issued to pay for acquisitions

Companies report basic and diluted [earnings per share](https://www.quantisnow.com/glossary/earnings-per-share). Diluted EPS assumes in-the-money options and warrants are exercised (using the treasury stock method) and that dilutive convertibles convert. The fully diluted share count adds all of these potential shares to the [shares outstanding](https://www.quantisnow.com/glossary/shares-outstanding).

Dilution is not automatically value-destroying. If the company raises money at a fair price and invests it well, value per share can rise. It hurts most when shares are sold cheaply or the cash funds ongoing losses.

## Why it matters for traders

Dilution is the dominant risk in small-cap and biotech stocks that burn cash. Traders track shelf capacity, active ATMs, warrant overhangs and cash runway to anticipate when the next raise is likely. Rising share counts quarter over quarter, visible on the 10-Q cover page, are a reliable tell. Large caps face slower dilution from stock compensation, often offset by buybacks.

## Example

Hypothetical Northwind Therapeutics (NWTX) has 100 million shares, and an investor owns 1 million, or 1.0%. NWTX sells 25 million new shares. The investor's stake falls to 1 million of 125 million, or 0.8%. If net income stays at $50 million, EPS falls from $0.50 to $0.40.

## FAQ

### How do I check if a company is diluting shareholders?

Compare shares outstanding on the cover pages of successive 10-Qs and 10-Ks, and check filings for shelf registrations, ATM programs and warrant exercises.

### Is dilution always bad?

No. Raising capital at a good price to fund profitable growth can increase value per share. It is harmful when shares are sold cheaply or proceeds fund continuing losses.

## Related terms

- [Shares outstanding](https://www.quantisnow.com/glossary/shares-outstanding.md): The total number of a company's shares currently held by all shareholders, including insiders and institutions, excluding treasury shares.
- [Earnings per share (EPS)](https://www.quantisnow.com/glossary/earnings-per-share.md): A company's net income available to common shareholders divided by its weighted average shares outstanding, reported as basic and diluted figures.
- [At-the-market (ATM) offering](https://www.quantisnow.com/glossary/at-the-market-offering.md): A way for a public company to sell new shares gradually into the open market at prevailing prices through a sales agent, off a shelf registration.
- [Warrants](https://www.quantisnow.com/glossary/warrants.md): Securities issued by a company that give the holder the right to buy its shares at a set exercise price before a set expiration date.
- [Convertible notes](https://www.quantisnow.com/glossary/convertible-notes.md): Debt securities that pay interest and can be converted into a set number of the issuer's shares, usually at a premium to the share price at issue.
- [Shelf registration](https://www.quantisnow.com/glossary/shelf-registration.md): An SEC registration that lets a company register securities in advance and sell them over time, typically up to three years, as market conditions allow.

## On Quantisnow

- [Shelf offerings and dilution](https://www.quantisnow.com/guides/shelf-offerings-and-dilution)
- [Live feed: Offerings](https://www.quantisnow.com/news/offerings)
- [Public offerings](https://www.quantisnow.com/categories/offerings)
- [Latest stock offerings and dilution](https://www.quantisnow.com/top/stock-offerings)