David Trainer, CEO of the independent investment-research firm New Constructs, recently wrote that Tesla stock is overvalued by roughly $1 trillion, reports Barron’s. Trainer, whose argument is based on math, says that Tesla shares could fall to about $150/share, or 88%.

Trainer says that Tesla’s $1.2 trillion valuation makes no sense, because it implies that Tesla owns 118% of the entire global passenger EV market, and would become more profitable than Apple by 2030. Plus, they would have to sell almost 31 million vehicles in 2030 to justify the current valuation, and many analysts predict annual sales of about 8 million cars by then. While many bulls believe Tesla will be more profitable than traditional automakers, Trainer believes they’ll be operating at profit margins along the lines of General Motors. If the prediction of 8 million cars in 2030 proves true, Tesla could yield earnings of about $30 billion annually, the article contends.

But there are plenty of Tesla bulls who believe that the company is the EV leader and will only increase its volume by an average of 50% a year for the foreseeable future. Given its skyrocketing stock over the last month, its recent sales of 100,000 vehicles to Hertz, and the overall positive outlook for EV in general, they have reason to be confident. But Trainer believes math doesn’t lie. His final word? “Putting it all together: Tesla provides poor risk/reward,” he wrote.