For example, a user submits $1000 in DAI to swap for the equivalent in BAT, but there’s not enough BAT in the DAI/BAT liquidity pool. However, there is enough BAT in the USDT/BAT pool. To that end, a more complex route is built: the DAI is first swapped for USDT in the auxiliary pool, then the USDT for BAT in the main pool, and then the BAT gets returned to the user. Liquidity aggregators allow transactions to find complex routes like that across liquidity pools, protocols, and even different networks. Naturally, the longer the route, the longer the swap will take, and the more it will cost to the user.
The most popular DEX aggregators include 1inch, Rango, ParaSwap, OpenOcean, Orion Protocol, and Matcha.