Tesla in ‘complete bubble territory’?

Shares of Tesla Motors are now overextended, Stephen Weiss of Short Hills Capital said Monday.

"This is complete bubble territory in terms of their valuation," he said. "Facebook isn't. So, if this should break, there's no getting out. You're going to take a massive haircut. Facebook has a more sustainable business, a more sustainable business model."

(Read more: Facebook a 'buy' on momentum: Weiss)

Recently, Tesla announced sales figures of its Model S electric sports car that showed the upstart automaker outsold Posrche, Volvo and Land Rover in California. Founder Elon Musk also said last week that the company was gearing up to sell cars in China.

Tesla stock has gained 406 percent year to date.

On CNBC's "Fast Money," Weiss said that the stock's momentum could hinge on what Musk does.

(Read more: Elon Musk: Tired but optimistic about Tesla's future)

"The only thing that matters here is that Elon Musk is smart enough, and I believe he is, to continue to guide the Street at a level at which he can exceed it with results," he said. "That'll drive the stock. But if he should miss, that'll come down quite a bit."

Rosecliff Capital's Mike Murphy said that Tesla was a momentum play.

"It's unbelievable what Elon Musk is doing with this company. It's unbelievable the numbers that the company is putting up there. And if you look at this now, valuation is out the window," he said.

(Read more: One college student rides the Tesla stock wave)

"So, you're not trading or buying or selling Tesla based on valuation. You look at the momentum on this name, you cannot escape the fact that this guy has put up everything he said he was going to with this company, and the sales are there to back it up. It looks like the run continues for Tesla."

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

Trader disclosure: On Aug. 26, 2013, the following stocks and commodities mentioned or intended to be mentioned on CNBC's "Fast Money" were owned by the "Fast Money" traders: Stephen Weiss is long AAMRQ; Stephen Weiss is short FB; Stephanie Link is long AAPL; Stephanie Link is long GS; Stephanie Link is long JPM; Stephanie Link is long WFC; Stephanie Link is long CSCO; Stephanie Link is long EBAY; Stephanie Link is long FB; Michael Murphy is long BAC; Michael Murphy is long C; Michael Murphy is long FB; As of 8/21 Jon Najarian is long AAPL; Jon Najarian is long EBAY; Jon Najarian is long GRPN; Jon Najarian is long MSFT; Jon Najarian is long QCOM; Jon Najarian is long MSG; Jon Najarian is long TOL; Jon Najarian is long JCP; Jon Najarian is long HLF; Jon Najarian is long CREE.