By Jonathan Davies

Wearable fitness technology company Fitbit saw revenues more than triple in the second quarter, in its first figures since becoming a publicly listed company.

Fibit, which makes wristbrands that monitor heart rate, calories burned, steps and sleep patterns, reported revenues $400 million (£256m), more than three times the $113m amount it posted in the same period last year.

Net income was $17.7m, up from $14.8m.

Fitbit listed its shares in June and its price has grown 160% since.

But shares dropped 15% after the announcement, due to falling gross margins. Its margins fell from 52% to 47% as it increased spending on development of its products.

Fitbit said it sold 4.5 million devices during the second quarter.