Front Running

Trading ahead of a known customer order to profit from the price move it will cause.

Front running is placing your own order ahead of a client's large order you know is coming, capturing the price impact at the client's expense — a broker buying for their own account moments before executing a customer's big buy. It is illegal for brokers because it betrays the client's interest and confidential information. The concept has modern echoes in high-frequency trading debates and in crypto, where bots watch pending public transactions and pay to jump the queue ahead of them.

The broker was barred from the industry for front running client orders with trades in his personal account.