Tesla Beat Delivery Estimates by 74,000 Vehicles -- and the Stock Had Its Worst Day in Nearly a Year. Here's Why.

Tesla (NASDAQ: TSLA) just posted its strongest second-quarter deliveries in its history, and shareholders responded by knocking about 7.5% off the stock in a single session -- its worst day in nearly a year. On Thursday, the electric-car maker said it delivered 480,126 vehicles in the second quarter, up 25% year over year, about 74,000 more than the 406,000 or so analysts had modeled.

By any normal reading, that is a blowout. So why did the stock fall so hard?

Tesla Cybercab. Image source: Tesla.

A record quarter the market shrugged off

Tesla's deliveries were not just a jump from a year earlier. They marked a 34% leap from the 358,023 vehicles Tesla delivered in the first quarter.

In short, deliveries have swung from declining a year ago to a second-quarter record -- exactly the kind of turn the bulls have been waiting for.

So what gives?

Part of the answer is that investors saw it coming. Tesla shares had climbed about 12% in the weeks before the report, so by the time the figure landed, much of the good news was already priced in. A sell-the-news reaction like this is common when a stock runs up into a catalyst.

But there is a deeper reason the market held back, and it has little to do with how many cars Tesla delivered.

What the market is actually pricing

There are a few underlying problems that investors may be concerned about.

First and foremost, there's a lingering question about how many of these sales were driven by a short-term spike in gas prices, as some consumers likely sought ways to save on transportation costs by switching to electric vehicles.

Then there are hints that the volume came at a cost. Production of 451,758 vehicles ran about 28,000 units below deliveries, meaning Tesla drew down existing inventory to hit the headline number rather than building stock. That raises a fair question about how much of the quarter was driven by end-of-quarter incentives.

Finally, some investors may worry that the company's push to introduce more aggressively priced models could be hurting margins. In the first quarter, Tesla's overall gross margin was 21.1%, with automotive gross margin excluding regulatory credits closer to 19%. If the second quarter's record volume was driven by more aggressively priced vehicles, those figures could slip even further. And for a stock priced the way this one is, that may matter more than the delivery count.

There is precedent for the worry. Tesla spent much of the past two years cutting prices to keep its factories full, and each cut chipped away at the profit on every car sold. Automotive gross margin has already fallen well off its peak.

And the stock is priced aggressively. At about 360 times earnings, Tesla trades like a company betting its future on autonomy and software (of course, it ultimately is doing this), not on selling more cars this quarter. A valuation like that, therefore, relies on soaring profits, so the market wants proof that the volume was profitable rather than always leaning on more speculative, longer-term business initiatives.

Of course, a record quarter shows demand is healthier than the bears feared. But the bull case here isn't really about how many cars Tesla sells this year. Instead, it rests on turning self-driving software and a nascent robotaxi fleet into high-margin, recurring revenue.

The figures and management commentary we really need will arrive on July 22, when Tesla reports full second-quarter financial results.

Personally, I wouldn't read Thursday's drop as a verdict on the quarter -- it looks more like the market deferring judgment and the stock taking a breather after a big run-up. The report needs to show that Tesla moved 480,000 cars without sacrificing margin. And, even more, Tesla will need to once again reassure investors that its higher-margin initiatives are making progress.

Daniel Sparks and his clients have positions in Tesla. The Motley Fool has positions in and recommends Tesla. The Motley Fool has a disclosure policy.