Open interest, or OI, is the total size of open perp positions in a market. It tells you how much exposure is currently outstanding, not how much trading happened during the day.
Volume measures activity over a period. Open interest measures active exposure still on the board.
Why OI matters
High or rising open interest can show that more traders are building positions. That can make a market more liquid, but it can also mean the trade is becoming crowded.
Low open interest can mean less participation. In thin markets, larger trades may move price more and exits can be harder during stress.
OI is not bullish or bearish by itself
For every long perp position, there is a short position on the other side. Rising OI does not automatically mean more buyers than sellers. It means more total exposure.
To interpret it, combine OI with price, funding, and volume.
Common OI reads
- Price up, OI up: new positions may be entering with momentum.
- Price up, OI down: shorts may be closing, or exposure may be leaving.
- Price down, OI up: new shorts may be pressing, or longs may be adding into weakness.
- Price down, OI down: positions may be closing or getting liquidated.
Why meme perps can get violent
When OI builds quickly in a meme market, a sudden price move can force many traders to exit at once. That can create a squeeze: shorts rush to buy back into a rally, or longs are forced to sell into a drop.
OI is context, not a crystal ball. Treat it like a crowding gauge.
Risk note: Crowded perp markets can unwind quickly. This article is educational content, not financial advice.