Open Interest: Open interest is the number of contracts that are still held and not yet settled. It shows how much money is currently riding on a market.

What it means

Open interest is the number of contracts that are still held and not yet settled. It shows how much money is currently riding on a market.

Example

If traders have bought 10,000 YES contracts and the matching 10,000 NO, open interest is 10,000. It falls when people close positions and resets at settlement.

Practical tip

Volume tells you activity; open interest tells you commitment. Rising open interest means new money is coming in.