By Conor White

The positive news in Tesla's second quarter earnings report outweighed the negatives for most investors, sending shares up more than 12 percent to their highest level in a month.

The electric carmaker announced that Model 3 production is up, but it posted losses of more than $700 million.

Some analysts have fundamental doubts about Tesla's future.

"It's a story stock," said Mark Spiegel, managing member at Stanphyl Capital. "What you have here are: bulls who couldn't care less about balance sheets or profit and loss statements; and you've got bears, or as I would call them, realists, who care a lot about that kind of stuff."

Spiegel counts himself in the latter group. He said in an interview Thursday on Cheddar that Tesla didn't do nearly enough to assuage fears about its future ー and that doesn't even account for all the other car companies eager for a bigger slice of the electric vehicle industry.

"There's a massive amount of competition coming for this company," Speigel said. "Between the Jaguar that's out now and the Audi, Mercedes, and Porsche coming out next year, it's going to destroy Model S and X sales, and that's where [Tesla's] margin isーwhatever margin they have."

And even though outspoken CEO Elon Musk behaved on this conference call, there's no telling what he will do next.

After reaching its production goal of 5,000 Model 3 cars per week, Tesla reports it now wants to churn out 10,000 per week, "as fast as we can."

Spiegel dismissed those numbers ー and Tesla more generally.

"They're a perennial over-promiser and under-deliverer," he said.

"The reason they keep putting out these aggressive numbers is it supports the stock, which is an absurd valuation. If Tesla were a normal car company losing this much money, the stock would be in the low single digits."

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