What Is Automated Market Maker?
An Automated Market Maker (AMM) is a smart contract system that uses mathematical formulas — most commonly the constant product formula (x × y = k) — to determine the price of assets in a liquidity pool. Instead of matching individual buyers and sellers through an order book, AMMs allow anyone to trade against a pool of assets contributed by liquidity providers.
How Automated Market Maker Works
The constant product formula ensures that as one asset is removed from the pool (bought), its price increases, and as the other is added (sold), its price decreases. The relationship is non-linear: larger trades create proportionally more price impact. Advanced AMMs like Uniswap V3 introduced concentrated liquidity, allowing LPs to focus their capital in specific price ranges for greater capital efficiency.
Why It Matters for Traders
AMMs democratized trading by eliminating the need for professional market makers and order books. They are the backbone of DeFi — Uniswap alone processes billions in daily volume. For traders, understanding AMM mechanics (price impact, impermanent loss, concentrated liquidity) is essential because it directly affects execution quality and the economics of providing liquidity.