Fahad Khan
AMM [ Automated Market Maker ]

AMM

What is an AMM (Automated Market Maker)?

An Automated Market Maker (AMM) is a type of market maker — similar in concept to firms like Citadel — but fully automated through smart contracts. They are mainly used in decentralized exchanges (DEXs) to keep the market liquid.

Unlike traditional order book systems, AMMs rely on algorithmic models that dynamically adjust prices based on the ratio of assets in a liquidity pool.

Who Built It and Why?

The idea of AMMs was first introduced by Vitalik Buterin in 2017, with working models arriving shortly after.

The point of an AMM is simple: Instead of matching a buyer and seller (like stock markets do), AMMs use liquidity pools and smart contracts to let anyone trade at any time.

This innovation made decentralized exchanges possible, removing middlemen and laying the foundation for modern DeFi.

The Fruit Basket Analogy 🍎🍌

Think of an AMM as a basket of fruits — say, apples and bananas.

  • If someone gives the basket bananas, they can take out apples.
  • If they give apples, they can take out bananas.

The system always balances the ratio of fruits inside the basket. That’s how trading works in an AMM.

Key Concepts in AMMs

1. Liquidity Pool = The Basket

Liquidity providers (LPs) are people who fill the basket with both fruits (tokens). They maintain a consistent ratio.

In return, LPs earn a small commission whenever someone trades.

2. How Prices Change

When you take Token A out, you must put in Token B.

Example:

  • If you keep taking apples and adding bananas, the basket ends up with too many bananas and fewer apples.
  • This makes apples more expensive (since they’re rarer).
  • Meanwhile, bananas get cheaper (since they’re abundant).

That’s how the AMM automatically sets prices.

3. Slippage (Big Trades Move Prices More)

If you suddenly dump a lot of bananas into the basket, the balance shifts drastically.

As a result:

  • Apples feel very rare.
  • You’ll get fewer apples per banana.

This price shift = slippage.

4. Impermanent Loss (IL)

Now let’s talk about the risk for liquidity providers.

Imagine you deposit 50 apples and 50 bananas into the basket.

  • If the price of apples suddenly skyrockets outside the AMM, traders will take apples and replace them with bananas.
  • When you withdraw your share later, you may end up with more bananas and fewer apples, which might be worth less than if you just held the tokens separately.

👉 This difference = impermanent loss.

It’s called impermanent because if prices return to their old levels, the loss disappears. But if they don’t, it becomes permanent.

Limitations of AMMs

  • Impermanent Loss — as explained above, LPs may lose value if prices move significantly.
  • Slippage — large trades can heavily distort prices.
  • Risk of Bugs/Exploits — since AMMs are smart contracts, bugs in code can be exploited.

The Future of AMMs

Concentrated Liquidity (More Efficient Pools)

Projects like Uniswap V3 introduced concentrated liquidity, making capital use much more efficient.

Cross-Chain and Omnichain AMMs

Right now, most AMMs only work on one blockchain.

For example, if you want to swap apples on Ethereum for bananas on Solana, you need bridges (which are risky).

Future AMMs will be:

  • Cross-chain, enabling swaps across blockchains directly.
  • Omnichain, meaning a single fruit basket spans multiple blockchains.

Projects like LayerZero are already building toward this vision.