Open interest in one sentence
Open interest (OI) is the total size of futures positions that are open right now: contracts that have been opened and not yet closed, settled or liquidated. On crypto exchanges it is usually quoted for perpetual futures, either in coins (contracts) or in US dollars.
Every futures contract has two sides. When a new buyer and a new seller trade with each other, one long and one short position appear and open interest rises by that size. When a trader closes a long by selling to someone who is closing a short, both positions disappear and OI falls. When one side is only handing its position to a new trader, OI does not change at all, even though volume was traded. That is why OI and volume measure different things: volume counts activity, OI counts what is still at stake.
Open interest vs volume: a worked example
Start with 10 open contracts. Each trade below is for 2 contracts, counted once, not once for the buyer and again for the seller:
- Both open: a new long buys from a new short. Volume adds 2 contracts; OI rises from 10 to 12.
- Both close: an existing long sells to an existing short who buys to close. Volume adds 2; OI falls from 12 to 10.
- Transfer: an existing long sells to a new long while the short stays open. Volume adds 2; OI stays at 10.
Total volume is 6 contracts, but OI ends where it started at 10. Volume measures trading activity over a period; OI measures the stock of contracts open at one time.
Measured BTC example (USD): OI at the snapshot is $21.22B, beside $32.09B of trailing 24h perpetual trading volume. Snapshot timestamp: 12 Nov 13:31 UTC. Both sums cover the same 13 perpetual markets on Aster, Binance, Bitget, Bybit, Gate, HTX, Hyperliquid, KuCoin, Lighter (9 venues).
Only markets with current, counted OI and known current 24h volume are included; MEXC and untrusted OI are excluded. The snapshot timestamp is not a separate observation time for each exchange field. These are a stock and a day's activity, not a forecast or a measure of how long positions stay open.
How exchanges report it
This site tracks open interest from every exchange on the coverage page, using their public APIs. MEXC is shown per market but is not added to totals; see data accuracy for why. The open interest page sums the included markets per coin across exchanges.
Exchange units vary. Coin-denominated open interest, such as Binance USDT-margined perps and Hyperliquid perps, is multiplied by the coin price to get a USD figure. Binance COIN-M perps instead report USD-denominated contracts: each BTC contract represents $100, and each other contract represents $10. For those markets, this site multiplies the contract count by its USD contract value.
USD open interest has one trap: it moves with price. If BTC rises 5% and nobody opens or closes anything, BTC open interest in dollars still rises 5%. To see whether positions were really added, take the price move out: a 7% USD OI rise during a 5% rally is only about 2% more contracts. The open interest screener does this before it labels a move, and the live box above shows both numbers for BTC.
Reading OI together with price
Open interest on its own has no direction. Every long has a matching short, so rising OI does not mean traders are bullish; it means more money is committed to the market on both sides. The useful signal comes from pairing the OI change with the price change over the same window:
- OI up, price up, often called new longs. More contracts are open and price is higher.
- OI up, price down, often called new shorts. More contracts are open and price is lower.
- OI down, price up, often called short covering. Fewer contracts are open and price is higher.
- OI down, price down, often called long unwinding. Fewer contracts are open and price is lower.
The names are conventional market shorthand, not an identification of traders. Every contract has a long and a short, so OI rises only when both sides open a position at once, and the price direction does not reveal which side initiated the trade.
The screener and the hourly states page apply one rule: a move gets one of these names only when price changed by at least 0.1% and price-adjusted OI changed by at least 0.5%; otherwise it is shown as below threshold. The price move is taken out of USD OI once, before the OI threshold is checked.
Right now: BTC OI is -1.04% over 24h while price is -1.50% (price-adjusted OI +0.46%), so currently the move is below threshold.
To see these combinations hour by hour, hourly price and OI states lists one USDT perpetual's recorded hourly price change next to its price-adjusted OI change, the USD OI move with the price move taken out, over the last 7 or 30 days. It counts an hour without enough recorded data as unavailable rather than guessing. The guide to hourly states and price-after-state outcomes explains the calculations and selection with synthetic examples.
These names are shorthand for what moved, not who traded, and not what happens next. A rally made of new longs can continue, or it can reverse sharply if those late longs are forced out. Add funding to the picture: when OI climbs and funding is also high, longs are crowded and paying for it; when OI climbs with negative funding, shorts are the crowded side.
Why traders watch it
Leverage build-up. A fast rise in OI without much price movement means leverage is piling in. Leverage has to be unwound at some point, and when it unwinds all at once you get a cascade of liquidations and a large candle.
Confirmation. A breakout on rising OI is backed by new positions; a breakout on falling OI is mostly shorts covering, which can run out of fuel once they are done.
Flushes. A sharp drop in OI during a sell-off shows positions being closed or liquidated. After a large flush, the market often carries less leverage than before.
Relative size. Comparing OI with daily volume or market cap shows how much of a coin's trading is leveraged. Small coins with OI close to their daily spot volume can move violently when positions unwind.
Limits to keep in mind
- OI is per exchange. A move on one venue can be traders moving between exchanges rather than new positions; summing venues, as the BTC open interest page does, reduces that.
- OI does not include spot holdings, options or positions on exchanges we do not track, so it is a partial view of total leverage.
- Our 1h, 4h and 24h changes come from 5-minute snapshots this site records. A newly listed coin shows "collecting history" in the longer windows until enough data exists.
- Hedged positions count too: a fund that is long spot and short perps adds to OI without a directional bet.
Used with price, funding and liquidations, open interest tells you how crowded a market is and which side is under pressure. It does not tell you where price is going. For the biggest moves right now, see the screener or Hyperliquid open interest.
Checked against the exchanges' own documentation on 21 October 2026: Binance API: open interest. Not financial advice.