Execution Welfare Across Solver-based DEXes

Decentralized exchanges (DEXes) have evolved dramatically since the introduction of Automated Market Makers (AMMs). In recent years, solver-based protocols have emerged as an alternative venue aiming to introduce competition for routing, access to offchain liquidity, and thereby improve end-user execution. Currently, these solver auctions are hosted on opaque backends, and the extent of price improvement they provide to end users remains unclear. We conduct an empirical study of the execution welfare that these protocols bring to users by analyzing data across different asset profiles (USDC-WETH and PEPE-WETH). Our results indicate that, compared to vanilla routing through Uniswap V2 or V3, solver-based protocols effectively enhance execution welfare for end users on DEXes within certain trade size ranges. This effect is most pronounced with USDC-WETH, a short-tail asset, and somewhat less significant with PEPE-WETH, a long-tail asset. Additionally, we identify execution welfare discrepancies across solver-based platforms (e.g., CoWSwap, 1inchFusion, UniswapX), revealing potential inefficiencies due to solver market structure, variations in liquidity profile and inventory depth among solvers. These insights highlight both the advantages and challenges of solver-based trading, underscoring its role in improving execution outcomes while raising concerns about market concentration and competition dynamics.