Jim Cramer cautioned against investors panic selling NVIDIA Corp (NASDAQ:NVDA) shares following news of a Justice Department subpoena over monopolistic practices. What Happened: On Tuesday, Cramer, the host of CNBC’s “Mad Money,” emphasized that Nvidia could see further declines but cautioned against panic selling due to the DOJ’s investigation. He urged investors to revisit previous instances where the DOJ scrutinized Nvidia for similar concerns. “OK Panickers, I am still telling people that Nvidia could go lower but if you are selling because of the Justice Department subpoena go back and re…