Fitbit has long been the most successful maker of high-tech wearables but one of the least successful initial public offerings among high-tech stocks. On Wednesday, both trends were on display—and how.

CEO James Park’s company reported third quarter results in line with analyst expectations, with revenue up 23% to $504 million and adjusted earnings per share of 19 cents. New fitness trackers like the Charge 2 and Flex 2 got mostly (but not entirely) rave reviews and sold pretty well.

And within minutes of Fitbit’s quarterly report hitting the wire, the stock lost over 30%, or almost $1 billion in market value.

There are many stocks that regularly see volatile trading after reporting earnings, like Amazon or Netflix. But even for those stocks, a 30% move in 10 minutes based on an earnings report is completely unheard of.

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The shocker wasn’t in the third quarter results, however. It was in Fitbit’s guidance about the all-important fourth quarter. Until now, Fitbit was at least a fast grower, even if there were questions about profit margins. But for the fourth quarter, Fitbit said it expected sales to grow only 2% to 5% from last year. As a point of reference, Fitbit’s sales increased 92% last year compared to the fourth quarter of 2014.

Park offered a couple of explanations. For one, sales in the Asia Pacific region are terrible and getting worse. They slipped 45% in the third quarter. “Growth there isn’t where we want it to be,” Park tells Fortune.

A second problem is that the company hasn’t been able to manufacture as many of the new $100 Flex 2 bands as customers wanted to buy. That will cut into sales by about $50 million in the fourth quarter, Park said.

Finally, the company didn’t manage its new product transitions well this year. Introducing the Flex 2 and $150 Charge 2 in August pulled some holiday purchases into the third quarter but left the line up a little drab for the fourth quarter.

In the future, Fitbit fit needs to get smarter about new product introductions, Park said. Asked about Apple’s iPhone event in early September every year, the CEO agreed “that’s what we’re striving for internally,” adding “we can execute better.”

The problems also arose after Apple aapl upgraded its smart watch just in time for the holidays. And Apple’s new emphasis for the series 2 Apple watch was much closer to Fitbit’s core fitness focus, potentially put the two companies in much more direct competition.

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The stock plunge, which occurred in after-hours trading on Wednesday, left Fitbit’s stock price at $8.94, an all-time low and down 30% from the regular market close. Shares were also down 55% from its $20 IPO price when the company went public in June, 2015.

Still, Park argued that Fitbit’s position remained solid and its future was bright. Excluding the three problematic issues that torpedoed the fourth quarter outlook, underlying consumer demand for Fitbit devices is growing 15% to 20%, he said. And the company has seen strong sales from repeat customers, with 40% of new products activated in the third quarter coming from existing customers who decided to upgrade.

“The overall category still has a lot of demand and growth,” Park says. “And overall our products are being well received.”

At another point in the interview, he added “our business is in no danger at all of going away.”

It’s the kind of thing you don’t often hear CEOs needing to assert. But when the stock market lops $1 billion in value off your company in 10 minutes, the usual rules don’t apply.