1inch's Fusion protocol is a significant upgrade to 1inch, designed to enhance the decentralized trading experience by making it more efficient, secure, and cost-effective - all in a simple and user-friendly interface.

Fusion provides protection against Maximal Extractable Value (MEV) or front-running attacks, which is crucial for maintaining fair trade execution and preventing potential financial loss with on-chain trading.

The protocol supports "gasless" execution, which means you don't have to need to hold a balance of native tokens (i.e. ETH, BNB, MATIC etc.) when trading. This is extra helpful in in a high gas fee environment, making your trades more cost-effective​.

Through Resolvers, Fusion is able to source liquidity from across the entire DeFi market, giving you optimal order matching while minimizing potential loss from negative price impact​.

Unlike classic 1inch swaps, in Fusion mode, the actual transaction for swapping your tokens is executed by a resolver. Resolvers are individuals or entities who compete to fill orders and also cover the associated gas fees. This competition follows a ‘dutch auction’ mechanism where the rate starts high and moves lower until your order is filled, the price moves below your desired slippage tolerance, or your order reaches its expiration time.