Sept. 15 (UPI) -- Tesla's share price surged by more than 8% in out-of-hours trade in New York on Monday after Elon Musk , the EV-maker's CEO, invested around $1 billion, his first open market purchase of the stock in more than five years. Traders and investors saw the purchase of the 2.57 million shares on Friday, his largest in the 20 years since he first took his first stake, as a sign of Musk's confidence in the firm he built into a global EV leader, helping the share price rally by more