While investors may be optimistic on Tesla's Model 3 production plans, which were tweeted by Elon Musk overnight, Bernstein is still skeptical the company will be able to produce the new electric car at a profit.
Analyst Toni Sacconaghi noted Musk's tweets, if accurate, mean Tesla will be able to manufacture the Model 3 at an annualized rate of more than 240,000 cars by the end of fiscal 2017 versus his total estimate for fiscal 2018 of 225,000 Model 3 vehicles.
"On net, initial production ramp for the Model 3 looks like it may be better than expected — but investors should continue to focus on whether the Model 3 can be produced profitably and with strong initial quality," Sacconaghi wrote in a note to clients Monday. "Specifically, we worry that if Tesla has struggled to make money (and produce GMs [gross profit margins] above 25%) on its $100,000 Model X and Model S sedans, that it may be difficult for it to make money on Model 3."
The analyst reaffirmed his market perform rating for Tesla and price target of $250, representing 31 percent downside from Friday's close.
Road testing for the Model 3 has been "limited" as Tesla decided not to make a prototype car, Sacconaghi noted. As a result, he said, he is concerned the new electric car may have quality issues and hurt the company's brand.
In addition, "Elon's historical track record of meeting production goals is mixed at best," he said.
A spokeswoman directed CNBC to Musk's comments during a first-quarter conference call with analysts, when he said, "[W]ith Model 3, I think we'll be roughly comparable with the best high-volume vehicle production lines in the world. Better in some respects, a little worse in others. But roughly comparable," according to a FactSet transcript.
Tesla shares traded roughly flat midday Monday. The stock is up nearly 70 percent this year versus the S&P 500's 8 percent return.