Needham analyst Rajvindra Gill warns the real valuation of Tesla shares is "closer to $200."

That would be 30 percent lower than Monday's open of about $292 per share, and 40 percent lower than the Aug. 6 close, the day before Tesla CEO Elon Musk floated taking the electric automaker private, saying "funding secured."

Gill, who downgraded Tesla shares on July 19 from hold to sell, told CNBC on Monday, "We think the valuation is closer to $200." He said Needham does not put out official price targets on its sells.

Tesla was not immediately available to respond to CNBC's request for comment.

Meanwhile, J.P. Morgan cut its December price target for Tesla back down to $195 per share, reiterating an underweight rating.

Analyst Ryan Brinkman explained to clients in a Monday note that he had raised his price target to $308 on Aug. 8 based on a 50 percent probability that Musk had in fact secured funding to take Tesla private at $420 a share.

"Our interpretation of subsequent events leads us to believe that funding was not secured for a going private transaction, nor was there any formal proposal," Brinkman said as reasoning for the price cut.

Needham's Gill also wondered about the financing and why Musk would tweet such an important development without a deal in place.

"There was no press release," Gill said. "There was no 8-K," a filing that's required with the Securities and Exchange Commission when companies announce major events.

The whole drama began with Musk's Aug. 7 tweet.

Am considering taking Tesla private at $420. Funding secured.

The public statement could be a violation of SEC rules.

On Aug. 13, Musk said in a blog post that he met with Saudi Arabia's sovereign wealth fund on July 31, and left that meeting "with no question that a deal with the Saudi sovereign fund could be closed."

On Friday, shares of Tesla had their worst day in two years after a New York Times feature outlined some serious struggles for Musk who was interviewed for the article.