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.

"I think the stock is grossly overvalued," he said. "I think the correction is not anywhere near done, and I'm selling the stock."

Dan Nathan of RiskReversal.com said that Tesla stock enjoyed a level of support at $135 a share, followed by $120.

It would remain to be seen beyond that, he said, adding, "There's a lot of room below."

But Wedbush Securities analyst Craig Irwin said that the latest bad news for Tesla wouldn't hurt the stock's long-term outlook.

(Read more: Bull market has 5 years ahead: Tom Barrack)

"Realistically, the biggest problem people are having with these cars is they're burning the tires out too quickly because they're enjoying pressing the pedal," he said. "I think we have to look at the circumstances under which these fires were initiated and give them the appropriate respect that we would give for a typical combustion-engine vehicle."

Irwin, who had a "buy" rating on the stock and a price target of $205 a share, also said that the National Highway Traffic Safety Administration might take a look at the Tesla Model S.

"I wouldn't be surprised if NHTSA does take a look, just to sort of check all the items off their list and make sure that they're doing things that would preserve maximum safety to the public," he said.

But there was solid support for its valuation, Irwin added.

(Read more: Tesla earnings and revenue beat; Shares plunge)

"Valuation is like a typical growth stock. You've got to look at the addressable market, and ask yourself, 'Do you believe?' So, the people that believe in Tesla—like myself—look out to the future and say, 'You know what? This company has a very interesting edge, and it has a trajectory which says that ... if they keep executing the way they have, they could easily be something like BMW over the next 20, 30 years.' If that's the case, what's the earnings going to look like, maybe $50, $60 a share?"

This week, Tesla reported third-quarter earnings excluding items of 12 cents a share, up from a loss of 92 cents a share in the year-earlier period.

—By CNBC's Bruno J. Navarro. Follow him on Twitter @Bruno_J_Navarro.