Glossary
Open interest
Open interest is the number of futures or options contracts opened and not yet closed, delivered or exercised. Each contract counts once, with a long and a short side, so the figure shows how many positions exist, not their direction.
Also called OI, open contracts, open commitments
See also
Open interest is the number of derivative contracts, futures or options, that have been opened and not yet closed, delivered or exercised. It measures how many positions exist at a moment, not how much trading took place. The CFTC defines it as contracts entered into and not yet offset, a long-standing futures statistic.
How open interest works: what counts is who opens and who closes
Every contract has a buyer and a seller. What matters is whether each side is starting a position or ending one:
- A new buyer meets a new seller: one long and one short are created, and open interest rises by one contract.
- A holder passes a position to a newcomer: open interest stays the same.
- A long holder and a short holder both close: the contract disappears, and open interest falls by one.
Long open interest always equals short open interest, as the CFTC notes, and exchanges count each contract once. Long/short ratios published by venues measure something else: Binance’s global ratio counts accounts.
Open interest vs volume: a worked example with numbers
Take a hypothetical market that opens the day with 100 contracts of open interest. Four trades of 10 contracts each follow.
| Trade | Buyer | Seller | Change | Open interest |
|---|---|---|---|---|
| A | New long | New short | +10 | 110 |
| B | New long | Existing long, closing | 0 | 110 |
| C | Existing short, closing | Existing long, closing | −10 | 100 |
| D | Existing short, closing | New short | 0 | 100 |
Volume is 10 + 10 + 10 + 10 = 40 contracts. Open interest moves by +10 + 0 − 10 + 0 = 0, ending where it began.
Reading open interest with price: a market convention, not a rule
CME Group’s lesson treats the figure as a gauge of sentiment and of the strength behind a trend: money moves into the contract when it rises, out when it falls. Traders have built a four-way reading on that idea, a habit rather than a rule:
- Price up, open interest up: new money is behind the rise.
- Price up, open interest down: shorts are covering, so the rise is thinner.
- Price down, open interest up: new shorts are arriving, or longs are holding on through the fall.
- Price down, open interest down: positions are being closed, sometimes by force.
On the Binance BTCUSDT perpetual, the count rose from 93,090 BTC at 12:00 UTC on 25 October 2026 to 96,721 BTC at 04:00 UTC on 27 October, a gain of 3,631 BTC or 3.90% (3,631 / 93,090). Over the same hours the price slipped about 0.9%, from about $80,400 to about $79,700, as our Asia morning report recorded. The data alone could not say which side started those positions.
Futures, options and units: where comparisons go wrong
Perpetual futures never expire, so their open interest only falls when traders close or are closed out. Dated futures and options lose a block of it at each expiry. Options are counted per strike and expiry, with calls and puts apart.
Units are the classic trap. Deribit’s documentation gives open interest in US dollars for perpetuals and inverse futures, but in the base coin for options and linear futures. A dollar total worked out from a coin count moves with the price even when nobody trades; the coin count does not.
CME bitcoin futures show how far the two can drift apart. CFTC weekly data for its Bitcoin (5 BTC) and Micro Bitcoin (0.1 BTC) contracts adds up to 148,417 BTC on 7 October 2025, the week of bitcoin’s record high, and 107,051 BTC on 13 October 2026, a fall of 27.9%. At Binance closing prices of about $121,300 and $83,100, our sum puts the dollar value at about $18.0 billion, then about $8.9 billion: a fall of 50.6%. The difference is the price.
Open interest and the crash of 10 October 2025
Near-record open interest and crowded bullish bets came before bitcoin fell from about $122,000 to about $105,000 on 10 October 2025, CoinDesk recalled a year later. Roughly $19 billion of positions across crypto markets were liquidated. Glassnode’s bitcoin count, reported by CoinDesk five days after the crash, dropped from about $70 billion (560,000 BTC) to about $58 billion (481,000 BTC). A liquidation cascade leaves that footprint: open interest falling hard along with the price.
No single figure for the peak holds up. Beside Glassnode’s $70 billion, Bitcoin.com reported roughly $100 billion from CoinGlass on 9 October 2025, also for bitcoin futures. A total means little until you know which venues and contracts went into it.
What open interest cannot tell you
The figure shows no direction and is not a buy or sell signal. A large number with high leverage means more positions that could be closed by force, but not when, or whether, that will happen.
Open interest: questions readers ask
Is open interest the same as volume?
No. Volume counts every contract traded during a period, so one contract changing hands ten times adds ten. Open interest counts the contracts still open at a given moment. Our example above shows 40 contracts traded with no net change.
Does open interest include shorts?
Yes, in the sense that every open contract has a long and a short side. Exchanges count each contract once, so 100 of open interest means 100 longs facing 100 shorts. That is why the figure cannot show whether buyers or sellers are in control.
How is open interest calculated?
Add the contracts created by opening trades and subtract those removed by closing trades. Both sides opening raises the count and both closing lowers it. One of each simply moves the position to someone else, so the count stays put.
What does rising open interest tell you?
It tells you positions are being added, so more money is committed to that contract. It does not show which way they lean: every new long has a new short facing it, and the price can move either way afterwards.
Where can you check open interest, and when does it update?
CME says open interest data comes out at the end of each day. The CFTC’s Commitments of Traders report, generally released on Fridays with Tuesday’s data, splits positions by trader type. Crypto venues update through the day, and aggregators add venues together, so their totals differ.