Order Flow
Order flow refers to the stream of trade instructions submitted by traders to trading venues. In the MEV context, order flow is a valuable commodity — exclusive access to incoming orders allows a searcher or builder to extract MEV from those trades before they become publicly visible. This has created an order flow market: wallets, dapps, and trading interfaces route user transactions to specific builders or searchers in exchange for a share of the extracted value (a rebate). Payment for Order Flow (PFOF) in crypto mirrors the traditional finance practice but with the added dimension of MEV extraction. Negative outcomes occur when order flow is routed to parties that extract more value from the trade than they return in rebates — a poor execution outcome for the trader. Positive outcomes occur when order flow goes to high-quality execution venues that minimize MEV leakage, such as RFQ systems, batch auctions, or private mempools with MEV-refund mechanisms.