Source: https://mochatrade.com/learn/glossary/option-open-interest

# Option open interest
URL: https://mochatrade.com/learn/glossary/option-open-interest
Last modified: 2026-10-17

Option open interest is the number of option contracts that exist at a strike right now, free on any option chain. The strike above the price with the most call open interest tends to act as a ceiling and the one below with the most puts as a floor, because [market makers hedging those contracts trade the stock](https://mochatrade.com/blog/mocha-markets-weekly-ccd). It belongs to [the layer of what is already priced](https://mochatrade.com/learn/start-here/how-to-read-us-market-news).

## Related terms

- Hedging: https://mochatrade.com/learn/glossary/hedging
- Open interest: https://mochatrade.com/learn/glossary/open-interest
- Options contract: https://mochatrade.com/learn/glossary/options-contract
- Put option: https://mochatrade.com/learn/glossary/put-option
- Implied volatility: https://mochatrade.com/learn/glossary/implied-volatility
- CPI: https://mochatrade.com/learn/glossary/cpi

Educational content only. Not investment advice. Leveraged products magnify losses as well as gains.