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What is open interest? Crypto futures, options, and open interest vs volume
Open interest is the number of futures or options contracts that are still open. Each contract has a buyer and a seller, so one long plus one short is one contract. Volume counts everything traded in a period; open interest counts what is left standing at the end. Rising open interest means new money and leverage are entering - it does not, on its own, tell you the direction.
Live example, BTC (22 Oct 2026, 01:40 UTC): open interest on Binance and Bybit is $13.32B (+3.2% in 24 hours, price +0.8%). Over the same 24 hours, BTCUSDT futures volume on Binance alone was $13.30B - 1.6x Binance's BTC open interest: in one day the market traded more than the total value of all positions still open. Live BTC open interest.
What open interest is
A futures or options contract always has two sides. When a buyer and a seller open a new contract between them, open interest rises by one. When they close it - by trading it away to each other or being liquidated - it falls by one. Open interest is therefore a count of positions that exist right now, not of trades.
A small example. Over one day:
| Trade | What happens | Volume | Open interest |
|---|---|---|---|
| Ann buys 1 from Bob | both open new positions | 1 | 1 |
| Cat buys 1 from Dan | both open new positions | 2 | 2 |
| Ann sells 1 to Eve | Ann closes, Eve opens - the position changes hands | 3 | 2 |
| Cat sells 1 to Dan | both close | 4 | 1 |
Four contracts traded, but only one position is still open at the end of the day. That gap is the whole difference between volume and open interest.
How open interest goes up and down
| Buyer | Seller | Open interest |
|---|---|---|
| opens a new long | opens a new short | +1 |
| opens a new long | closes an old long | unchanged |
| closes an old short | opens a new short | unchanged |
| closes an old short | closes an old long | -1 |
Forced closes count too: a liquidated long is closed with a market sell, so a wave of liquidations shows up as a sudden drop in open interest.
Open interest vs volume
| Volume | Open interest | |
|---|---|---|
| Measures | contracts traded during a period | contracts still open at a moment |
| Type | a flow - resets every period | a stock - carries over |
| Rises when | anyone trades | new positions open on both sides |
| Falls when | trading slows | positions close or get liquidated |
| Tells you | how active the market is | how much exposure and leverage stays in |
In crypto futures, daily volume is usually a multiple of open interest, because so much trading is opened and closed within hours. A day with heavy volume but flat open interest is mostly positions changing hands; a day with rising open interest is new exposure being built.
In USD or in contracts? A trap
Crypto sites usually show open interest in dollars. Dollar open interest moves with price even if no one opens a single new position: if BTC rises 10%, dollar open interest rises 10% on the same contracts. To see whether positions really grew, compare the change in open interest with the change in price - or look at it in coins. On our open interest page the 24-hour price change sits next to the open interest change for exactly this reason.
Open interest in options
For options, open interest is counted per contract: each strike and expiry has its own number. A large open interest at one strike means many traders hold positions there - but it does not say whether they bought or sold the options, so it is not a bet on direction by itself. Crypto options trade mostly on Deribit; the same buyer-and-seller logic applies, and the numbers are often summarized as open interest by strike and as the put/call ratio.
Reading open interest with price
| Open interest | Price | Common reading |
|---|---|---|
| up | up | new longs are opening |
| up | down | new shorts are opening |
| down | up | shorts are closing or being squeezed |
| down | down | longs are closing or being liquidated |
Open interest and liquidations
Open interest is the raw material for liquidation heatmaps: when it rises, new leveraged positions appear, and each has a liquidation price. A sharp fall in open interest during a fast move is usually liquidations - compare the same hour on live liquidations. High open interest together with extreme funding rates means one side is crowded and paying for it.
Common mistakes
- Reading dollar open interest without price. Part of the change is just price.
- "Rising open interest is bullish." It means more positions on both sides.
- Treating one exchange as the market. Our numbers cover Binance and Bybit; other venues add more.
- Confusing open interest with volume. A huge volume day can leave open interest unchanged.
FAQ
What is open interest?
The number of futures or options contracts still open. One long plus one short is one contract.
What is the difference between open interest and volume?
Volume counts everything traded in a period; open interest counts positions still open at the end. Volume shows activity, open interest shows how much exposure stays.
What does open interest mean in options?
The number of option contracts of a given strike and expiry still open - many positions there, but not a direction by itself.
Is rising open interest bullish?
Not by itself: new longs and new shorts open together. It is read with price, and that reading is still a rule of thumb.
Live data: open interest for 20 coins · BTC open interest · ETH open interest · SOL open interest · XRP open interest