The Difference Between Open Interest and Volume

Volume and open interest measure different things in futures markets.

Volume counts the contracts traded during a period.

Open interest measures the number of outstanding contracts that remain open.

A high-volume session doesn't automatically mean open interest increased by the same amount. Every futures trade has both a buyer and a seller, and open interest changes according to whether positions are opened or closed.

Understanding this distinction helps avoid oversimplifying market activity.

Before interpreting a data point, I make sure I know exactly what it measures.