Detroit: Elon Musk has sold 4.4 million shares of Tesla stock worth roughly $4 billion, most likely to help fund his purchase of Twitter. Musk reported the sale in a filing with the Securities and Exchange Commission on Thursday. The shares were sold over the past few days, at prices ranging from $872.02 to $999.13.   The world's richest man, who is the CEO of Tesla, tweeted that he ...