Metrics & Analysis

What is Open Interest?

The total number of outstanding option contracts at a given strike.

📖 Complete Definition

Open interest represents the total number of option contracts that are currently open and not yet closed, exercised, or expired. High open interest indicates liquidity and ease of entering/exiting positions. Changes in open interest show whether new money is flowing into or out of a contract. It's different from volume, which counts daily trades.

💡 Examples

  • Open interest of 50,000 contracts indicates a liquid, actively traded strike
  • Rising open interest with rising price suggests new buying interest

Frequently Asked Questions

How do I use open interest in trading?

High OI indicates liquid strikes with tighter spreads. Unusual OI changes can signal institutional positioning. Compare OI to volume to gauge if positions are being opened or closed.

🔗 Related Terms

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Open Interest - Definition & Examples | Options Trading Glossary | Options Education - ImpliedOptions