Price tells you where the market went. Open interest tells you whose money moved it: new positions or old ones being closed.

What open interest is

Open interest is the total value of futures contracts that are open and not yet closed. Every futures trade has two sides, a long and a short, so open interest is not split into buyers and sellers. It measures something else: how much money is currently committed to leveraged positions.

It rises when both sides open new positions and falls when positions are closed, either voluntarily or through liquidation.

How it differs from volume

Volume counts every trade in a period. A trader who opens and closes a position within an hour adds volume twice and leaves open interest unchanged. Volume measures activity; open interest measures how much risk has built up.

Four combinations with price

Price up, open interest up. New money is entering and the move is backed by positions. If funding is also high, the rally is mostly leveraged longs.

Price up, open interest down. The rally is shorts closing. These moves can be sharp but have little fuel: once the shorts are gone, there is nobody left who has to buy.

Price down, open interest up. New shorts are opening and sellers are confident. If the drop stalls, those shorts become fuel for a bounce.

Price down, open interest down. Longs are leaving or being liquidated. A sharp fall in open interest during a fast move almost always means a liquidation wave, after which the market often calms down.

Why the exchange breakdown matters

Traders behave differently on different venues. The open interest page shows each exchange's share and how BTC open interest has changed over time. We only count USDT-margined contracts, so the totals add up across venues without currency conversion.

How to use it

Read open interest together with funding and the long/short ratio. Fast growth in open interest with high funding and a long-heavy ratio is a market overloaded with leverage. The liquidation heatmap shows where that leverage would be flushed.