JPMorgan Trader Who Helped in Spoofing Convictions Avoids Prison

A former JPMorgan Chase & Co. precious metals trader who admitted to spoofing and market manipulation avoided prison on Tuesday because he helped the government win convictionsof his supervisors.

Christiaan Trunz spent three days last year testifying in the trial of Michael Nowak, who ran JPMorgan’s precious-metals operation, and chief gold trader Gregg Smith. Trunz described for federal jurors in Chicago how Smith and Nowak used huge buy and sell orders, which they quickly canceled and never intended to execute, to push prices in the direction they wanted to benefit the bank or its customers.

Trunz pleaded ...