Shares of Tesla Motors are overvalued and have much further to fall, Gordon Johnson of Axiom Capital Management said Thursday.
"I think Tesla's a $50 stock," he said. "Essentially, people are valuing this car, again, on a gen-three model for which there is no prototype. Tesla's cars cost about $80,000 to $90,000 right now. They're using, essentially, laptop batteries. They're packaging Panasonic laptop batteries into these car batteries, which are effectively the bulk of the cost. Those batteries have been scaled up. How are they going to get more cost out of that? I don't know."
Tesla stock closed down 7.5 percent to close at $139.77 per share following news of a third battery fire in two months.
(Read more: Yet another Model S fire puts heat on Tesla)
Johnson told CNBC's "Fast Money" that the stock would see lower levels.