Front-Running

The illegal practice of a broker or trader executing orders on a security for their own account while taking advantage of advance knowledge of pending orders from clients. For example, if a broker knows a client is about to place a massive buy order, buying shares first and profiting from the resulting price increase is front-running. In decentralized crypto markets, MEV (Maximal Extractable Value) bots perform a technological version of front-running on blockchain transactions.