Tesla shaken up by recent executive moves, Musk behavior

Tesla's shares dropped the most in two years on Friday, rocked by the departure of its accounting chief after just a month and mounting investor concerns about CEO Elon Musk's behavior after he smoked marijuana on a live webcast. Investors in the electric carmaker are on edge after a tumultuous August, during which Musk proposed and then abruptly pulled the plug on a go-private deal.