Transaction Order Manipulation

Definition ∞ Transaction order manipulation involves intentionally altering the sequence of pending transactions within a blockchain block to gain an unfair advantage. This practice, often a component of Miner Extractable Value (MEV), includes front-running, back-running, and sandwich attacks. Actors with control over block production or privileged access to transaction order flow can execute these maneuvers. It degrades market fairness and can result in financial losses for regular users.
Context ∞ Transaction order manipulation is a significant and widely reported issue in crypto news, particularly within decentralized finance (DeFi), where it leads to substantial value extraction. The current discussion centers on developing and implementing technical solutions, such as proposer-builder separation (PBS) and fair ordering policies, to mitigate these predatory practices. Future advancements aim to create blockchain architectures that inherently resist transaction order manipulation, thereby fostering a more equitable and secure trading environment.