Volume counts activity
Volume measures how much changed hands during a selected interval. Venues may report it in base units or quote-value notional, so confirm the unit before comparing markets.
Open interest counts what remains open
Open interest rises when new contract exposure is created and falls when exposure is closed. Every contract has both a long and a short side, so it should not be read as a count of bullish traders.
Use context, not a single signal
Rising price with rising open interest can suggest new participation, while falling open interest can suggest positions are closing. These are interpretations, not deterministic signals.
The same trade can affect the measures differently
Volume counts completed transactions during a period. Open interest counts contracts that remain open. When two traders create a new long and short, both volume and open interest can rise. When two existing counterparties close, volume rises while open interest falls. If exposure transfers from one trader to another, volume can rise while open interest is unchanged.1
Neither measure proves direction. Rising open interest can accompany both bullish and bearish positioning because every open contract has two sides. Use price, funding, basis, liquidation data, and market context rather than treating one statistic as a forecast.12
A four-case reading framework
Rising price with rising open interest is often described as new participation joining the move. Rising price with falling open interest can reflect position closure. Falling price with rising open interest can reflect new exposure on both sides, while falling price with falling open interest can reflect liquidation or voluntary exits.1
These are descriptive hypotheses, not rules. Open interest does not identify which side is informed, and venue data may differ in timing or scope. Confirm with funding, basis, volume, and event context.12