Nvidia could be looking at an investigation from the U.S. Department of Justice over antitrust concerns.Last week, reports from Bloomberg, Reuters, and CNBC presented some conflicting details regarding a supposed U.S. Department of Justice (DOJ) subpoena issued to Nvidia (NVDA -0.03%) as part of an alleged antitrust investigation. Nvidia's public relations team denies that the company has been subpoenaed, but the mere idea of such action led to some selling activity for the semiconductor stock since the new ...