Open interest is the total number of futures (or options) contracts that have been opened and not yet closed, offset, or delivered. Every contract has a long on one side and a short on the other, and open interest counts each such pair once. It is published once a day by the exchange, with a one-day lag, for each contract month and for the whole market.
Think of it as the amount of money committed to the market. Rising open interest means capital is flowing in and new positions are being built; falling open interest means positions are being closed and capital is leaving.
Volume is how many contracts changed hands during a session. Open interest is how many positions are still on the books at the end of it. Volume resets to zero each day; open interest carries over.
A single contract can trade several times in a day — inflating volume — without changing open interest at all, if each trade just passes an existing position from one holder to another. Open interest only moves when a position is genuinely created or genuinely retired:
Open interest is a confirmation tool. The classic combinations traders watch:
None of these is a signal on its own — they describe what kind of flow is behind a price move, which helps judge whether it is likely to continue.
In most commodity markets open interest is concentrated in the front few contract months and thins out further along the curve. As each contract nears expiry, holders who do not want delivery roll their positions forward, so open interest migrates from the expiring month to the next. A deferred contract with very little open interest can have stale or unreliable settlement prices, which matters when you are reading a forward curve.
The CFTC Commitment of Traders report takes the total open interest and breaks it down by who holds it — commercial hedgers, managed money, and other reportable traders — which is why open interest and positioning are usually read together.
Open interest is a two-sided number: for every extra long there is an extra short, so a rise does not tell you which side is "winning." It is also reported with a lag, and around expiry the roll makes month-by-month figures jump for purely mechanical reasons. Use it to characterise participation and liquidity, not as a timing indicator.
Commodity Hub shows open interest and CFTC positioning next to price and curve data for every tracked market. Open the app to see current figures.