After the bell on April 19, Tesla announced Q1 results that sorely disappointed even its ardent Wall Street fans. Five price reductions so far this year, designed to bolster demand, lowered average sales prices so markedly that operating margins fell from over 19% a year ago to 11.4%. All told, earnings cratered by almost one-fourth. The battery-on-the-blink performance was far from the fabulous growth story that Elon Musk’s long been selling investors. On the news, no fewer than seven analysts pared their price targets for the shares. At midday on April 20, Tesla’s stock had fallen 9.3% to $164.40, erasing $58 billion in market cap, an amount equal to more than one-third the valuation of Netflix.

But for one leading analyst, the selloff isn’t remotely big enough to bring the EV king’s shares in line with its fundamentals. David Trainer, founder and CEO of investment research firm New Constructs, believes that using the most realistic projections for the likes of sales and earnings, Tesla’s worth something like $28 a share or one-sixth its current price—which by the way, is down 60% from its peak of $415 reached in late 2021. “Tesla remains hugely overvalued,” Trainer told Fortune, pointing to a $517 market cap that still amounts to twice the combined valuations of Toyota and Volkswagen.

Trainer is unswayed by the narrative that Tesla’s not mainly a car company but a tech juggernaut that will set the pace in self-driving vehicles and produce the next-gen batteries its rivals will rely on. Put simply, he believes that the flood of new, mostly bargain-priced models issued by every big competitor will substantially lower Tesla’s profitability going forward. For Trainer, it’s all about the numbers. First, what Tesla’s future earning must equal to justify its current cap, and second, assessing its true value based on reasonable projections for sales and profits. In a new report, Trainer gives his estimates showing that Tesla flunks on both criteria.

How fast must Tesla grow to be worth a cap of over $500 billion?

For both exercises, Trainer uses one of the most reliable tools in finance, discounted cash flow analysis. To see what Tesla must do to merit an over half-a-trillion valuation, he plugged in the sales, profit, and capex numbers over the next eight years that discount back to that gigantic benchmark. For Tesla to get there, Trainer reckons that it must grow sales at a 28% compound rate through 2031, and achieve after-tax operating margins of 13%, 80% higher than Toyota’s current level of 7%. Tesla also needs to keep capex growth at one-third of its current rate, despite the requirement of constantly building new factories to sustain that exploding output.

If it hits those supercharged metrics, Tesla would garner $100 billion in net operating profit by 2031, 60% more than Toyota, Stellantis, GM, and Ford all make combined, ascending to what Apple has earned in the past four quarters. Trainer’s verdict: It’s mission impossible. It won’t happen.

What’s Tesla worth using optimistic but reasonable projections for its fundamentals?

Trainer’s “most likely” scenario holds that Tesla will indeed get much bigger in the years ahead, but generate only slightly more profit than it books today. Once again, the big headwind will be the onslaught of low-priced EVs vying for the same customers. Trainer thinks it’s probable that Tesla grows sales fast, at between 20% and 30% a year in 2023, 2024, and 2025, and at 10% in the five out years. The rub: He forecasts that its operating margins will fall from 13% in 2023 to 7% in the years beyond. Hence, its earnings won’t grow much from here, despite fast-waxing sales.

Still, Tesla would rank as an industry titan eight years hence, boasting annual sales of 4.5 million vehicles, 3.5 times the figure over the past four quarters. That’s equal to 43% of all the Toyotas customers purchased in the past 12 months, and equal to all the newly bought Volkswagens. If Tesla manages to meet these still challenging numbers, Trainer believes its stock, at present, should be fetching $28 a share.

“It’s all playing out as we predicted in previous reports,” Trainer told me. “Tesla’s really admitting that the car business won’t make the money Musk was projecting, and it’s clear that claims the ancillary business will supply the needed extra growth are a shell game.” Elon Musk, the Music Man of EVs, has built a great company but also sold followers on an incredibly overblown vision. In turn, the believers awarded Tesla an incredibly inflated market cap. Tesla can remain a great company. Its stock, Trainer argues backed by strong logic, is headed for disaster.