In the traditional financial system (TradeFi), if you want to trade a stock or ETF, you need a “Market Maker”—typically a large bank or firm—to be on either side of your trade to ensure there is enough liquidity available to buy or sell.
In decentralized finance (DeFi), the big banks are replaced by a protocol called Automated Market Maker (AMM). They are considered the underlying engine that powers decentralized exchanges (DEXs).
In this guide, we explore how these software programs have revolutionized digital assets trading by allowing anyone to buy, sell, or provide liquidity without a central authority.
What is an AMM?
An Automated Market Maker (AMM) is a protocol that exists on decentralized exchanges (DEX) that relies on a mathematical formula to price assets. Unlike traditional exchanges that use an order book to match specific buyers with specific sellers, AMMs allow you to trade against a pre-funded “pool” of tokens, known as “Liquidity Pools.”
How Does an AMM Work?
Instead of maintaining an order book, where buyers and sellers wait to be matched with each other, an AMM utilizes Liquidity Pools to allow users to trade directly against a smart contract containing their desired assets.
Regular DEX users, or Liquidity Providers (LPs), deposit their crypto assets into a pool from which others trade. The exchange rewards LPs for locking their crypto in the pool to facilitate trades, earning a small portion of the pool’s transaction fee. When a trader wants to swap from one asset to another, eg, ETH for USDC, they don’t have to wait for another person to sell the USDC to them. Instead, they simply interact with the smart contract, which then releases the equivalent amount of USDC from the pool automatically for the ETH they wish to trade.
Most AMMs maintain a constant balance of assets using a mathematical formula called the ‘Constant Product Formula’: X x Y = K
- X is the amount of Asset A in the pool
- Y is the amount of Asset B in the pool
- K is the fixed constant that must remain the same
When a trader buys a large amount of Asset A (X), its supply decreases. To keep the total value (K) constant, the price of A must increase relative to Asset B (Y). This ensures the pool never actually runs out of liquidity, though the price shifts based on the size of the trade.
Advantages and Disadvantages of AMMs
Here are the advantages and disadvantages of Automated Market Makers (AMM) that you need to be aware of before using them:
Advantages:
- Permissionless – AMMs do not need sign-ups or ID checks. Users only need a crypto wallet to connect to these smart contracts.
- 24/7 Liquidity – AMMs have no operating hours. Users can trade 27/7/365 as long as the liquidity pool has sufficient funds to execute the transaction.
- Passive Income – Anyone can become an LP for an AMM and earn fees. Before DeFi, market maker roles were exclusively reserved for traditional financial firms.
Disadvantages:
- Slippage – This is the difference between the price you expect to pay for an asset and the price you actually pay for it. In shallow pools, large trades can move the price significantly, resulting in potential losses.
- Impermanent Loss – This is a risk for LPs if the price of one asset in the pool moves drastically compared to the other.
Popular AMM Platforms
As of 2026, the DeFi landscape has evolved into high-performance, multi-chain ecosystems. Here are the most popular AMMs of the year:
- Uniswap v4
- Jupiter (Solana)
- Curve Finance
- PancakeSwap (v4)
Summary
Automated Market Makers have revolutionized finance by turning “market making” into a public utility. By replacing human brokers with smart contracts and liquidity pools, AMMs provide a decentralized, always-on marketplace for any digital asset. While risks like impermanent loss exist for those providing capital, the efficiency and accessibility of AMMs continue to make them the backbone of the decentralized finance (DeFi) world.
