The Californian-based company has smashed previous revenue estimates of $319 million. Fitbit has managed to shift 4.5 million trackers, including its Fitbit Surge and Charge HR, in the second quarter of 2015, up from 3.9 million in the first.
In early 2015, Fitbit managed to take the title of the biggest selling manufacturer of wearable tech, but now with Apple being secretive about its Watch numbers, we can't be sure who is on top.
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Still, Fitbit has seen particular popularity outside the US, where fitness tracker sales have risen 250% year-on-year.
Fitbit's CEO, James Park, said in a statement: "Our second quarter results included our highest quarterly revenue in the eight-year history of Fitbit. In the quarter, we introduced new features and services, expanded brand awareness, increased global distribution and further penetrated the corporate wellness market."
Fitbit pulled off the third biggest IPO of 2015, after raising over $732 million from 36.6 million shares sold at $20 a pop. And since then share prices have gone up 150%.
Bizarrely this Q2 earnings call has seen shares drop 11% in trading, following an initial 4% growth. This could be down to a 5% drop in Fitbit's takings after costs, or investors could be taking their profits while they can - what goes up must come down.
Fitbit continues to have a strong position in the fitness market and these results will rub salt in the wound of Garmin's second quarter financial results. Although losing out to Misfit in China sales, Fitbit is still ruling the fitness tracker roost.