Open interest
Higher open interest means deeper economic activity in a market.
Prediction Markets 101 editorial team Updated April 16, 2026 1 min read
Definition
Open interest is the total amount of a contract held across all positions. On Kalshi, it measures how much collateral is locked in active contracts.
Plain-English explanation
Open interest differs from volume — volume is total trades over a period, open interest is current outstanding positions. A market can have high volume and low open interest if traders are quickly opening and closing, or low volume and high open interest if positions are held for a long time.