Open interest imbalance

The difference between total long and total short open interest in a market. Pool-based protocols price trades against it, charging less to trades that reduce the imbalance and more to trades that widen it.

Definition

Open interest imbalance is the gap between the two sides of a market. When longs and shorts are evenly matched, they are each other’s counterparty and the imbalance is near zero. When one side dominates, the difference has to be carried by someone else.

Who carries it

On an order-book venue, other traders do, and the funding rate is the price they charge.

On a pool-based venue such as GMX, the liquidity pool is the counterparty for the unmatched portion. That means the liquidity providers are effectively holding the opposite exposure to the crowd, and their result depends on whether the crowd is right.

Why it changes your fees

Protocols that carry the imbalance charge for it. A trade that pushes the imbalance wider is taking on risk the pool has to absorb, and is priced accordingly, often through both a higher fee and a price impact adjustment on the execution price. A trade in the direction that closes the gap does the pool a favour and is charged less, sometimes with a favourable price impact instead.

The practical consequence is that the same position costs different amounts depending on which way the market is already leaning, and that difference is knowable before you trade.

What to check before you open

The current imbalance and the direction you intend to take. Being on the crowded side means paying more to enter and, on some protocols, running into open interest caps that refuse the trade entirely.

Where you will run into it

On the market pages and fee breakdowns of pool-based perpetual DEXs, and indirectly in the funding rate of order-book venues, which is the same phenomenon priced a different way.