CHICAGO (BLOOMBERG) - The former head of the JPMorgan Chase & Co precious-metals business and his top gold trader were convicted in Chicago on charges they manipulated markets for years, handing the United States government a win in its long crackdown on bogus "spoofing" orders. Michael Nowak and Gregg Smith were found guilty on Wednesday (Aug 10) by a federal jury after a three-week trial and more than eight days of deliberations. Prosecutors presented evidence that included detailed trading records, chat logs and testimony by former co-workers who "pulled back the curtain" on how Nowak and Smith moved precious-metals prices...