Transaction Reordering

Definition ∞ Transaction reordering is a method by which a malicious actor or miner alters the sequence in which transactions are included in a block. This manipulation can be used to exploit discrepancies in transaction timing or influence the outcome of certain operations, particularly in decentralized finance. Understanding this concept is key to recognizing potential system manipulations.
Context ∞ The current discourse on transaction reordering is closely tied to discussions about miner extractable value (MEV) and front-running strategies on blockchains like Ethereum. These strategies aim to profit from the predictable ordering of transactions in the pending transaction pool. Future developments are expected to focus on mitigating MEV through changes in block production mechanisms and the implementation of privacy-preserving transaction technologies.