Open Interest (OI)
Open interest, or OI, measures the total outstanding derivatives positions that remain open and have not yet been closed or settled.
✦ Key Insight
Open interest helps traders assess participation and leverage in futures and perpetual markets. Trading volume tells you how much trading occurred during a period. Open interest tells you how much exposure remains open. A rapid increase in OI can suggest that traders are adding new leveraged positions.
✕ Common Misconceptions
Treating rising OI as bullish
Confusing OI with volume
Ignoring funding
Comparing incompatible exchange data
Assuming OI reveals exactly how many longs versus shorts exist
Ignoring leverage concentration
Detailed Explanation
How It Works
When new positions create additional open contracts, OI increases.
When positions are closed, OI decreases.
Traders frequently compare OI with price:
Price rising + OI rising: new positioning may be entering.
Price rising + OI falling: some of the move may involve short covering.
Price falling + OI rising: new bearish or hedging positions may be entering.
Price falling + OI falling: long positions may be closing or liquidating.
These are interpretations, not fixed rules.
FAQs
Is open interest available for spot trading?
Not in the same sense. It primarily relates to derivatives contracts.
Is high OI dangerous?
Not inherently, although high leverage can increase liquidation risk.
Can OI fall quickly?
Yes, particularly during large liquidation events.
In Practice
Dig Deeper
Funding rate
A funding rate determines periodic payments between long and short perpetual-futures traders to help keep the contract price near the spot price.
Volume
Trading volume is the amount of an asset or contract traded over a specified period.
Liquidation
Liquidation is the forced reduction or closure of a leveraged or collateralized position when required risk or collateral thresholds are breached.
Leverage
Leverage allows a trader to control a position larger than the capital committed to support it.