Liquidity Pool

A liquidity pool works by pairing two (or sometimes more) tokens inside a single smart contract, with an automated market maker algorithm setting the exchange rate between them purely from the ratio of reserves. The most common version, the constant product formula (x times y equals k), means every trade shifts the balance of the two assets and therefore moves the price along a fixed curve, with no order book or matched counterparty required.

Anyone can become a liquidity provider by depositing an equal value of both tokens, receiving LP tokens that represent their share of the pool and entitle them to a proportional cut of trading fees, usually between 0.05% and 1% per swap depending on the protocol and pool type. This model, pioneered by early AMMs and refined by platforms like Uniswap, replaced the market-maker role traditional exchanges rely on with code and open participation, becoming a core building block of decentralized finance alongside lending and yield farming.

The main risk is impermanent loss: if the two tokens' prices diverge after deposit, arbitrage traders rebalance the pool against the provider, leaving them with less value than if they had simply held the assets. Stablecoin and correlated-asset pools carry far less of this risk, while volatile pairs can erase fee income entirely. Smart contract bugs and depegging events add further exposure, so pool selection matters as much as the yield on offer.