(Reuters) – Wearable fitness device maker Fitbit Inc’s revenue forecast for the key-holiday shopping quarter fell well short of analysts estimates, hurt by stiff competition from rival device makers.

Shares of the company, which also reported lower-than-expected quarterly revenue, plummeted more than 30 percent in extended trading on Wednesday.

Fitbit forecast revenue of $725 million to $750 million for the key holiday-shopping quarter, well below analysts’ estimates of $985.1 million, according to Thomson Reuters I/B/E/S.

Fitbit is the leader, according to research firm IDC, in the market for wearable devices such as wristbands that track the wearer’s calories, sleeping patterns and heart rate.

But, the San Francisco-based company is facing increased competition from devices made by rivals such as Xiaomi, Garmin Ltd, Samsung Electronics and Apple Inc.

Fitbit, which launched two new fitness wristbands Charge 2 and Flex 2 in late August, said it sold 5.3 million devices in the quarter ended Sept. 30, up from 4.8 million a year earlier.

Analysts on average had expected shipments of 5 million devices, according to research firm FactSet StreetAccount.

Still, Fitbit’s revenue increase of 23.1 percent to $503.8 million in the third quarter ended Sept. 30 missed analysts estimates of $506.9 million.

Net income fell to $26.1 million, or 11 cents per share, from $45.8 million, or 19 cents per share. Excluding items, it earned 19 cents per share, in line with analysts’ expectations.

Fitbit’s shares have fallen about 13.5 percent since Sept. 7 when Apple launched its latest smartwatch.

(Reporting by Laharee Chatterjee in Bengaluru; Editing by Savio D’Souza)