Market StructureOI
Open Interest
The total number of derivative contracts still outstanding and not yet closed or settled at the end of a session.
What Open Interest means
Open interest counts the contracts that remain open in an exchange-traded derivative. It increases by one only when a new buyer and a new seller create a fresh contract, stays unchanged when an existing position transfers between participants, and falls when both sides close. Unlike volume, which resets each session, open interest is a running total of committed positions and is published by the exchange after the close.
Traders read rising open interest alongside rising price as evidence that new money is supporting a move, and falling open interest as a sign that positions are being unwound. In currencies the concept applies to futures and options, not to spot, since there are no standardised contracts to count in OTC forex. Spot traders still use it indirectly through futures positioning reports, which break down open interest by category of participant each week.
Worked example
If euro futures open interest rises from 680,000 to 720,000 contracts while price advances, new long positions are being established rather than shorts merely covering.
Related terms
- Currency FuturesStandardised, exchange-traded contracts to exchange currency at a set price on a fixed future settlement date.
- VolumeA measure of trading activity - genuine contracts traded on an exchange, but only tick counts on a retail forex platform.
- Commitment of Traders (COT)A weekly CFTC report breaking down open interest in US futures markets by trader category, widely used as a positioning gauge.
- Over-the-Counter (OTC)Trading conducted bilaterally between two counterparties rather than through a centralised exchange and clearing house.
- Sentiment AnalysisMeasuring how market participants are positioned and how bullish or bearish they are, often used as a contrarian filter.
Frequently asked questions
What does Open Interest mean in forex trading?
The total number of derivative contracts still outstanding and not yet closed or settled at the end of a session.
How does Open Interest work in practice?
Traders read rising open interest alongside rising price as evidence that new money is supporting a move, and falling open interest as a sign that positions are being unwound. In currencies the concept applies to futures and options, not to spot, since there are no standardised contracts to count in OTC forex. Spot traders still use it indirectly through futures positioning reports, which break down open interest by category of participant each week.
What is an example of Open Interest?
If euro futures open interest rises from 680,000 to 720,000 contracts while price advances, new long positions are being established rather than shorts merely covering.
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