Billionaire Elon Musk contemplated taking Tesla private as early as 2016, his former chief of staff Sam Teller said at a hearing over Musk's 2018 tweet claiming he had "funding secured" for taking Tesla private. Sometimes Musk compared Tesla with closely held space startup SpaceX, Teller said. "He said there were...headaches...from running a public company," Teller quoted Musk.