Market signals
Open interest
Understand what open interest counts in a derivatives market, how it differs from volume, and what it can and cannot reveal.
Also called: OI, outstanding interest
Definition
Open interest — Open interest is the total amount of derivative contracts or exposure that remains open and has not been offset or settled. It changes when positions create or remove outstanding exposure. Unlike trading volume, which counts activity during a period, open interest describes the stock of active contractual exposure at a point in time.
In plain English
Volume asks how much changed hands during a period. Open interest asks how much derivative exposure is still outstanding. A market can trade heavily while open interest stays flat if participants mostly transfer or close existing exposure.
Every contract has economic exposure on both sides. Reporting conventions avoid simply counting one long and its matching short as two separate contracts, although venues may publish open interest in contracts, asset units, or notional value.
How it works
When two participants create new opposing positions, open interest increases. When both close matching exposure, it decreases. When a new participant takes over an existing participant’s side, ownership changes but the amount still open can remain the same.
For perpetuals, open interest has no expiry cycle forcing it to roll into a later contract. Liquidations, voluntary closes, and new positions can change it continuously.
Why it matters
Open interest helps describe participation and outstanding exposure. Analysts often compare it with price, volume, funding, and liquidity, but the number does not reveal every trader’s leverage, entry, liquidation price, or motivation. Rising open interest alone is not bullish or bearish.
Worked example
Alice opens one long contract while Bob opens the matching short. The market now has one contract of open interest, not two. Later both close that contract, reducing open interest back to zero.
If Alice instead transfers her long exposure to Cathy while Bob remains short, trading volume increases but one contract remains open. Open interest therefore stays at one.
How it works on Lynx
Lynx tracks long and short open interest for each traded instrument. The difference between those sides—the open-interest skew—determines which side pays funding and contributes to the rate.
That mechanism is designed around Lynx’s isolated liquidity pools: funding discourages one-sided trader exposure that would otherwise increase the corresponding pool’s counterparty risk.
Common misconception
Rising open interest does not prove that new money is betting on higher prices. Every new contract has opposing exposure, and direction requires additional context.
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Related definitions and practical guides.
Sources and review
Written by Lynx Editorial. Reviewed by Lynx Protocol Team on July 31, 2026. Review policy.