Open Interest


Open interest is the total number of outstanding derivative contracts, such as options, swaps or futures that have not been settled for an asset. Open interest provides an accurate picture of derivative trading activity including whether money flowing into options, swaps and futures markets are increasing or decreasing.


To understand open interest, we must first explore how options and futures contracts are created. If an options contract exists, it must have had a buyer. For every buyer, there must be a seller since you cannot buy something that is not available for sale. The relationship between the buyer and seller creates one contract. The contract is considered "open" until the counterparty closes it. Adding up the open contracts, where there are a buyer and seller for each, results in the open interest.

API Endpoints








Our Open Interest endpoints are available via REST API for latest and historical (time series) data as well as WebSockets for real-time data.

This table outlines how far back our Open Interest data goes across the different exchanges within the future, swaps and option markets:

ExchangeFutures Market Start Date*Options Market Start Date*Swaps Market Start Date*
FTX US**X2022-01-14X

*These dates represent the oldest start date we have for Open Interest data across all contracts
**As of 2022-11-12, we stopped supporting FTX, but historical data will remain available

Frequently Asked Questions

Why is knowing open interest important?

  • Open interest is a measure of the flow of money into a futures, options or swaps market. If open interest is increasing, this represents new or additional money coming into the market while decreasing open interest indicates money flowing out of the market. While this isn’t indicative of whether or not the trades will be profitable, it is a good measure of interest in the market or more specifically, a particular instrument.

Can open interest be used as an indicator of market momentum?

  • Yes. Since open interest represents additional money and interest coming into a market, it is generally interpreted to be an indication that the existing market trend is gaining momentum or is likely to continue.