Wrong stock jumps 11,700% since Elon Musk's 'Use Signal' tweet
Shares of US medical device company Signal Advance have soared as much as 11,708% since Tesla CEO Elon Musk tweeted "Use Signal" on January 7, referring to the encrypted messaging app. Signal Advance had no revenue from 2014 to 2016. "We strongly recommend people do their due diligence and always invest with care," its CEO Chris Hymel said.