What Is a Liquidity Pool?

Traditional exchanges use order books where buyers and sellers post prices. Liquidity pools replace this with an automated mathematical formula (like Uniswap's x*y=k) that determines prices based on the ratio of tokens in the pool. When someone buys Token A, they add Token B to the pool and remove Token A, shifting the ratio and price. This system enables 24/7 trading without requiring a counterparty to be available at any specific price point.

Impermanent loss is the primary risk for liquidity providers. It occurs when the price ratio of pooled tokens changes after deposit. If one token's price rises significantly, the pool rebalances by selling the appreciating token — meaning you end up with less of the winning token than if you had simply held it. The loss is "impermanent" because it reverses if prices return to the original ratio. However, in volatile markets, impermanent loss can exceed trading fee income.

To become a liquidity provider, you typically deposit equal values of two tokens into a pool (e.g., $500 of ETH and $500 of USDC). In return, you receive LP tokens representing your share of the pool. As trades occur, you earn a proportional share of fees — usually 0.3% per swap. You can withdraw your tokens plus accumulated fees at any time by returning your LP tokens. Concentrated liquidity (Uniswap V3) lets you specify a price range for greater capital efficiency.