Two former precious metals traders at JPMorgan Chase and a co-worker who handled hedge fund clients face trial starting 8 July in the climax of a seven-year Justice Department campaign to punish alleged market manipulation.

The criminal trial in Chicago is the third in two years to focus on a style of deceptive trading known as spoofing. Prosecutors have alleged that former members of JPMorgan’s precious metals desk routinely sent orders they intended to quickly cancel to rig the price of gold and silver futures contracts, earning big profits for the bank over eight years.