Shares in Fitbit dropped by almost 15 per cent in after hours trading, as the health and fitness accessory group unveiled revenue of $711.6m (£502.7m) for the final quarter of 2015, up from $370.2m in the same period of 2014.
The group's stock tanked, despite smashing expectations of $648m in revenue. It also reported earnings per share (EPS) of $0.35, well ahead of forecast $0.25 EPS.
The firm saw sales leap on a yearly basis, up from $745.4m in 2014 to $1.86bn. The company issued revenue guidance of $2.4bn to $2.5bn for 2016, and said new product introductions and geographic expansion would drive this growth.
Profits rose to £64.1m from $39.2m on a quarterly basis, while the profits for the year rose to $175.7m from $131.8m.
The number of devices sole in the final quarter of last year rose to 8.2m from 5.3m, while over the year the number of units sold almost doubled from 10.9m to 21.4m. Registered device users climbed to 29m from 11m in 2014, while the number of active users rose to 16.9m from 6.7m.
“We believe we are beginning 2016 with strong customer engagement and retention, an accelerating pace of innovation and competitive differentiation, and a foundation of significant revenue growth and profitability in 2015,” said James Park, Fitbit co-founder and chief executive.
“I am very optimistic about our growth opportunities and long-term vision as a broader digital health company.”