Concept

Open Interest

Open Interest is a Breadth, Sentiment & External Data concept. The Library holds 3 implementations, each one a working definition you can pull into Quant.

+ OI-price divergence. OI-weighted funding

Top Open Interest indicators

The top custom implementations, built on the original standard Open Interest formula.

3 total

Every Open Interest implementation here is strategy-ready: open one in Quant, set your rules, and it backtests automatically.

Open Interest Chart preview

Open Interest Chart

Indicator

Open Interest Inflows & Outflows preview

Open Interest Inflows & Outflows

Indicator

Liquidation Estimates (Real-Time) preview

Liquidation Estimates (Real-Time)

Indicator

What is Open Interest?

Open interest is the total number of derivative contracts (futures, options, perpetual swaps) currently open: entered into and not yet closed, settled, or liquidated. Every contract has one long and one short, so OI counts outstanding positions, not traders or trades. It rises only when a new buyer and a new seller both open, falls when both sides close, and stays flat when an existing position simply changes hands. That makes it fundamentally different from volume: volume measures turnover within a period, while open interest measures the standing stock of exposure that remains after the period ends.

The classic futures reading pairs the direction of price with the direction of OI. Price up with OI up suggests new longs are driving the move, fresh money confirming the trend. Price up with OI down suggests short covering, a rally powered by exits that tends to run out of fuel. Price down with OI up marks aggressive new shorts, and price down with OI down marks long liquidation. In crypto perpetuals, OI combined with the funding rate shows how crowded and how expensive positioning is, and sudden OI flushes are the footprint of liquidation clusters being cleared.

How to read Open Interest

Open interest plots as a series under price, in contracts, coin terms, or notional dollars; the information comes from pairing its changes with price changes.

  1. 1Plot OI for the instrument you trade and check the unit. For crypto perps, aggregated OI across exchanges gives the fuller picture, while per-exchange OI shows where positioning concentrates. Notional (dollar) OI rises with price even when contract counts do not, so know which you are reading.
  2. 2Classify each price swing with the matrix: rising OI in the direction of the move means new positioning is driving it, while falling OI means the move is powered by position exit, either covering or liquidation.
  3. 3Mark extremes and abrupt changes: record OI built into a level means crowding, and a vertical OI drop paired with a long wick is a forced-liquidation flush rather than voluntary selling.
  4. 4Cross-check the crowd's direction with funding and cumulative volume delta before deciding which side is trapped.

How it's calculated

The total number of derivative contracts currently open, meaning created but not yet offset by an opposite trade, delivered, or exercised.

OI⁡t=OI⁡t−1+Qopen−Qclose\operatorname{OI}_t = \operatorname{OI}_{t-1} + Q_{\text{open}} - Q_{\text{close}}
ΔOI⁡t=OI⁡t−OI⁡t−1\Delta \operatorname{OI}_t = \operatorname{OI}_t - \operatorname{OI}_{t-1}
Per matched trade: both sides opening new positions adds the traded quantity to OI⁡, both sides closing existing positions subtracts it, and one side opening while the other closes leaves OI⁡ unchanged.\text{Per matched trade: both sides opening new positions adds the traded quantity to } \operatorname{OI}\text{, both sides closing existing positions subtracts it, and one side opening while the other closes leaves } \operatorname{OI} \text{ unchanged.}
Every open contract pairs one long with one short, so OI⁡t equals total open long contracts and also equals total open short contracts.\text{Every open contract pairs one long with one short, so } \operatorname{OI}_t \text{ equals total open long contracts and also equals total open short contracts.}
OI_t: open interest at the end of period t, in contracts
OI_(t-1): open interest at the end of the prior period
Q_open: total quantity from trades during t in which buyer and seller both opened new positions
Q_close: total quantity from trades during t in which buyer and seller both closed existing positions
ΔOI_t: net change in open interest over period t
t: reporting period (traditional futures venues publish once daily after settlement)

Open interest is tallied by the exchange or clearinghouse from position records; it cannot be derived from price or volume alone.

Volume counts every contract traded, while OI nets out position transfers, so a heavy-volume session can leave OI flat.

Futures OI is a contract count; crypto venues often quote it in notional terms (contracts × contract size × price) and update it continuously.

How traders use it

  • As trend confirmation: a breakout accompanied by rising OI and supportive funding has new commitment behind it, while the same breakout on falling OI is more likely a covering pop.
  • As OI-price divergence: price grinding to new highs while OI bleeds off warns that the advance is running on exits rather than fresh demand; the same logic applies inverted at lows.
  • As squeeze fuel: a large OI build with stretched funding identifies a crowded side, and the eventual unwind tends to be fast because closing is forced rather than chosen.
  • As positioning context in options and dated futures: OI by strike feeds analyses like option strike walls, and OI migration around expiry explains mechanical flows that have nothing to do with opinion.

Open Interest vs related concepts

Volume Delta: Delta measures which side is hitting the tape within a period, the aggressor flow. Open interest measures how many positions remain open afterward. Big delta with flat OI is churn between existing players, not new exposure.

Funding Rate: Funding is the price of holding a perpetual position, a skew measure; OI is the size of positioning. Crowding reads best when both align: heavy OI plus persistently one-sided funding.

COT Analysis: COT reports break weekly futures open interest down by trader category (commercials, large speculators), answering who holds the exposure. Raw open interest only says how much exists.

Concept family

Breadth, Sentiment & External Data

63 concepts mapped · 63 in the Library

Open Interest FAQ

Turn Open Interest into a trading strategy.

Take any implementation from this page into Quant, then build on it, backtest it on real data, and keep refining it in conversation.