What Is Open Interest?

Open interest is the total number of derivative contracts, whether futures, perpetuals, or options, that are currently open and have not been closed out or settled.

Traders watch open interest to gauge how many positions are live in a market at a given moment, and how that count shifts as new contracts are opened and old ones are closed. This page explains what the number measures, how it differs from trading volume, and how it is read next to price. It is descriptive throughout.

What open interest counts and how it changes

Open interest rises by one when a new buyer and a new seller open a fresh contract between them. It falls when both sides close an existing contract. When a new trader takes over one side from an existing holder, the contract simply changes hands and the outstanding count stays the same. That last case matters: activity can be busy while the number of open positions sits still. The dated exchange traded contract behind the futures count is described in what a futures contract is.

Open interest versus trading volume, the common confusion

Volume counts how many contracts changed hands during a period, say a single day. Open interest counts how many contracts are still outstanding at one point in time. The two often move together, but not always. Volume can be high while open interest is flat, which happens when traders pass the same contracts back and forth without adding net new positions. Volume resets each period, while open interest carries over until positions are closed.

Reading rising or falling open interest alongside price

Open interest is read next to price to describe whether live positioning is growing or shrinking, and on which side. Rising open interest with a rising price means new money is opening positions. Rising open interest with a falling price means new short positions are opening. Falling open interest means positions are being closed, a process traders call deleveraging. Each of these describes the flow of positions. None of them says where price travels next.

Open interest in crypto perpetuals versus the CFTC futures data

In crypto, perpetual contracts have no expiry, so open interest can build over long stretches rather than resetting at a settlement date, and it is watched next to the funding rate and long/short ratio. Kresmion tracks open interest across the major perpetual venues alongside the funding rate and the long/short ratio. In regulated futures, the CFTC Commitments of Traders (COT) report publishes open interest each week, which is where positioning extremes such as COT net-long positioning are measured over longer horizons.

A worked example from 30 July 2026

On 2026-07-30 at about 15:20 UTC, Kresmion's derivatives feed showed Bitcoin perpetual open interest of about $6.9 billion on Binance, roughly 106,700 BTC, with long positions about 56% of the total. Ethereum perpetual open interest stood at about $4.5 billion. Read descriptively, the dollar figure states how much notional sits in open Bitcoin perpetual positions on that venue at that timestamp, and the 56% long share states how those positions split between the two sides. It does not state where either price settles next.

Key takeaways

Frequently asked questions

Does open interest predict which way price will go?

No. Open interest measures how much is at stake, not which way a market resolves. A large or growing number tells you many positions are live and capital is committed, but it is silent on direction. Both sides of every contract are counted, so a high figure never favors longs or shorts on its own.

What is the difference between open interest and volume?

Volume is a flow, counting how many contracts traded over a period and resetting when that period ends. Open interest is a stock, counting how many contracts remain open at a moment and carrying forward until they are closed. A day can post heavy volume with little change in open interest if traders mostly hand existing contracts to one another.

Why does open interest matter in crypto perpetuals?

Perpetual contracts never expire, so open interest can build over long stretches rather than resetting at a settlement date. Watching it next to the funding rate and the long/short ratio shows how crowded and how leveraged a market has become. It describes the size of live positioning, and it does not forecast the next move.

Where can I see open interest for regulated futures?

The CFTC Commitments of Traders (COT) report publishes open interest for regulated futures markets each week, broken down by category of trader. That weekly series is where longer-horizon positioning extremes are measured. This page is information, not investment advice.

--- Source: Kresmion derivatives feed, 2026-07-30 (open interest snapshot about 15:20 UTC); CFTC Commitments of Traders report. Kresmion Research.