What Is a Liquidity Pool? Definition & Example

A liquidity pool is a smart contract holding reserves of two or more tokens that anyone can trade against. Instead of matching individual buyers with sellers through an order book, trades execute directly against the pooled reserves at a price set by a formula.

Liquidity providers deposit both assets in the required ratio and receive LP tokens representing their share. They earn a cut of every swap fee generated by the pool, proportional to their share, and can withdraw their position plus accrued fees at any time.

The design solved a genuine problem: bootstrapping liquidity for a new token without professional market makers. Anyone can supply liquidity, permissionlessly, and trading works from day one. That accessibility is what made decentralised exchanges viable.

The costs are real and often understated. Impermanent loss means providers underperform simply holding whenever prices diverge, and for volatile pairs this frequently exceeds the fees earned. Smart contract risk is unavoidable — pools have been drained by exploits. And in pools containing a token with no established value, providers can be left holding the worthless side of a rug pull.

Evaluate a pool on three things: expected price divergence between the assets, actual fee volume rather than advertised APY, and whether the yield is paid in real fees or in emissions that will be diluted away. Stablecoin pairs minimise divergence risk; volatile pairs need heavy volume to compensate for it.