SAN FRANCISCO, United States — Fitbit Inc. lost almost a third of its market value in late trading after the wearable gadget maker's sales forecast for the crucial holiday shopping season fell well short of analysts' expectations.

Revenue in the current quarter will be $725 million and $750 million, the company said Wednesday. That compares with an average analyst prediction of $981.3 million. Fitbit forecast fourth-quarter profit excluding certain costs of 14 cents to 18 cents a share, missing average analyst estimates of 17 cents.

"We are starting to see some headwinds in our business," chief executive officer James Park said on a conference call. "But we think the market opportunity ahead is large."

Park has been trying to prove that Fitbit is more than a one-trick pony by doubling down on research and development and re-positioning the company as a digital health platform. It is facing growing competition from lower-cost wearable makers like Xiaomi Corp. and players like Apple Inc. at the high end.

In September, Fitbit rolled out two new devices, the Charge 2 and Flex 2, and there was positive initial demand that raised optimism about holiday sales. However, the company’s forecast on Wednesday suggested that early bullishness was misplaced.

"It's a seasonal business. You have a significant amount of sales in the fourth quarter. They're basically saying it's going to be worse than expected," said Charlie Anderson, analyst at Dougherty & Co. "The last time they reported earnings, they had not released their new products. I'm sure they are looking at real time data about how their products are doing and they're making this decision of lower expectations."

Fitbit shares plummeted 29 percent to $9.09 in extended trading. The stock closed at $12.81 during regular trading earlier on Wednesday.

Third-quarter revenue grew 23 percent from a year earlier to $504 million. That missed analysts’ average estimate of $508.7 million. Sales in the Asia-Pacific region dropped 45 percent, suggesting pressure from cheaper wearables made by Xiaomi and other rivals.

Sales in Asia were "not what we had hoped," Park said. "We’re hoping to refine our marketing based on continued research."

By Selina Wang; editors: Robert Fenner, Alistair Barr and Jillian Ward.

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