Open interest

Open interest is the total value or number of derivative contracts, such as futures, perpetuals or options, that are currently open and have not been closed or settled. Every open contract has a buyer and a seller, so open interest counts each matched pair once.

It is different from trading volume. Volume counts every trade, including positions opened and closed on the same day; open interest measures how much leveraged exposure remains in the market at a given moment.

Traders read it alongside price. Rising open interest with a rising price suggests new money entering long positions; rising open interest with a falling price suggests new shorts. Very high open interest relative to the market means lots of leverage, which increases the risk of large liquidation cascades in either direction. A sudden drop in open interest usually means positions are being closed or liquidated. Data sites aggregate open interest across major exchanges for bitcoin and other large coins.