Inside MEV on Ethereum: Builders, Searchers, and the Hidden Fees You Pay

Maximal Extractable Value (MEV) is the profit captured by reordering or inserting transactions on Ethereum. While MEV can improve DeFi efficiency, it also drives up gas fees and creates an invisible “tax” on users through practices like sandwich trading. Specialized actors—searchers, builders, and relays—dominate this ecosystem, with Flashbots providing auction infrastructure. Though MEV extraction is lucrative, it centralizes block production and raises concerns around censorship, regulation, and taxation as governments begin scrutinizing these hidden flows of revenue.