AMMs can only enable new markets when liquidity providers supply liquidity (e.g. multiple tokens for given trading pairs or pools). In return for providing liquidity, liquidity providers are rewarded with trading fees when other users swap tokens. For example, when traders swap two tokens on Uniswap v3, they are currently charged anywhere between 0.05% and 1% on top of the gas fees. These fees are distributed pro-rata to liquidity providers of the pair based on the percentage of total liquidity that they have provided.