Futures education
Futures volume vs open interest: trades and outstanding contracts
An opening trade, a transfer and a closing trade can generate five contracts of volume while leaving just two contracts open.
Volume counts trading; open interest counts outstanding contracts
Futures volume is the number of contracts traded during a specified period. Open interest is the number of contracts still outstanding, not yet closed by an offsetting trade or fulfilled through final settlement or delivery. Volume measures activity over time; open interest measures what remains open at a point in time.
Count each matched contract once. A buyer purchasing one contract from a seller adds one to volume, not two. Likewise, one outstanding long paired with one outstanding short represents one unit of open interest. Open interest counts contracts, not traders: one trader can hold several contracts.
Sources: CFTC futures glossary · CME volume and open-interest columns · CME: What is volume?
Five contracts trade; two remain open
Consider one hypothetical futures contract month starting with no open positions. These are the only trades, and there are no expirations, deliveries or other position adjustments. Buying to open creates a long position; selling to open creates a short. Selling to close reduces an existing long; buying to close reduces an existing short.
When Aria transfers one of her three longs to Cora, Ben still holds three shorts: open interest stays at three. Cora later sells her one long to Ben, who closes one short. Aria then holds two longs, Ben holds two shorts and Cora is flat. The remaining open interest is two, while total traded volume is 3 + 1 + 1 = 5.
| Trade | Buyer | Seller | Volume so far | Open interest |
|---|---|---|---|---|
| 3 contracts: both open | Aria opens 3 longs | Ben opens 3 shorts | 3 | 3 |
| 1 contract: one opens, one closes | Cora opens 1 long | Aria closes 1 long | 4 | 3 |
| 1 contract: both close | Ben closes 1 short | Cora closes 1 long | 5 | 2 |
Sources: CFTC futures glossary · CME volume and open-interest columns · ICE: Open-interest counting
Match the contract, time period and report
A chart's volume bar may cover five minutes, while the open-interest figure beside it comes from an end-of-day report. Check the date attached to each field before treating them as simultaneous measurements. CME's daily volume and open-interest report is preliminary at the end of the trading day; its official Daily Bulletin follows the next morning, and figures can change.
- Contract month: a single expiry and a total across all expiries measure different scopes. Do not compare one month's volume with product-wide open interest as if both described that month.
- Trading period: compare completed sessions of the same length, or clearly label an incomplete session. Volume accumulated so far today is not a full day's volume.
- Venue and product filters: CME's Globex column covers electronically traded contracts; its total Volume column covers all CME Group venues. Also check whether a report includes futures only or combines futures and options.
Sources: CME daily volume and open-interest reports · CME volume and open-interest columns · CME: What is volume?
Neither number identifies the next price move
An increase in open interest adds both a long and a short for every new outstanding contract. It does not, by itself, show that there are more buyers than sellers or that the market will rise. Volume alone also cannot distinguish new positions from closing trades. The transfer in the example increases volume without changing open interest.
Volume and open interest help describe market activity, but neither is a count of orders available to fill yours now. For that, inspect current bid and ask prices and order-book depth. ICE treats the bid-ask spread as a separate liquidity measure alongside volume and open interest; a large daily total is not a guaranteed execution price.
Sources: CME: What is volume? · ICE: Measures of market liquidity · CME volume and open-interest columns