Open Interest
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In Brief
Open interest is the total number of outstanding derivative contracts — such as perpetual futures — that have not yet been closed or settled, used as a key indicator of market participation and liquidity.
What Is Open Interest?
Open interest (OI) is the total number of open derivative contracts — such as perpetual futures — that have not yet been closed, expired, or settled. It is one of the most widely
tracked metrics in derivatives markets, used to gauge trader participation, liquidity, and the strength of a prevailing trend.
Unlike trading volume, which counts every transaction over a time period, open interest counts only contracts that are currently live. A single long-short pair counts as one open
interest, regardless of how many times it's traded.
How Does Open Interest Work?
When a trader opens a new position, open interest increases by one contract.
When a trader closes an existing position, open interest decreases by one contract.
When two existing traders simply exchange a position (one closes, one opens), open interest stays the same.
Open interest is typically reported per market (BTC-PERP, ETH-PERP, etc.) and as a total across the exchange.
Volume vs Open Interest
| Feature | Open Interest | Trading Volume |
|---|---|---|
| What it measures | Contracts currently open | Contracts traded over time |
| Reporting cadence | Snapshot at a point in time | Cumulative over 24h, 7d, etc. |
| Purpose | Market participation level | Trading activity level |
| Changes when | Position opened or closed | Every trade executed |
How Traders Use Open Interest
Trend Strength Indicator
Rising OI + rising price → new money entering, trend is strong
Rising OI + falling price → new short positions, bearish conviction
Falling OI + rising price → short covering, weakening rally
Falling OI + falling price → long liquidation, capitulation
Liquidity Gauge
Higher open interest generally means better liquidity and tighter spreads — it's easier to enter and exit large positions without slippage.
Market Sentiment Proxy
Extreme highs in open interest often precede volatility events (both squeezes and flushes), as crowded positioning becomes vulnerable.
Open Interest Across Platforms
Open interest is tracked separately for each derivatives platform. Centralized exchanges like Binance and Bybit historically dominate total crypto OI, but on-chain platforms like
Hyperliquid have captured growing share as self-custody perps become more popular.
Limitations of Open Interest
Doesn't distinguish longs from shorts — OI counts contracts, not direction
Platform-specific — global OI requires aggregating data across multiple exchanges
Not a leading indicator on its own — most useful when combined with price and funding rate
Open Interest and Trust Wallet
When trading perpetual futures through Hyperliquid or Aster DEX via Trust Wallet, users can view real-time open interest for each market directly in the trading interface. Open interest is a key data point for assessing market participation before entering a position.