Shares in Fitbit vaulted 48 percent to close at $29.68, after the initial public offering at $20 a share raised up to $732 million (roughly Rs. 4,660 crores).
The market value for Fitbit was some $4 billion (roughly Rs. 25,466 crores) based on the IPO.
Fitbit was a pioneer of "wearable computing," where it faces longtime rivals such as Jawbone and new competition from Apple Watch and Android-powered smartwatches which also track fitness.
Fitbit said it has sold more than 20.8 million of its clip-on or wrist-worn devices, and claimed to have a leading position in the US fitness-focused activity tracker market last year.
Like other fitness trackers, Fitbit's wearable devices equipped with sensors feed information to smartphone applications that tap into the analytic power of computers in online data centers.
Fitbit had a profit of $131.8 million last year and just shy of $48 million (roughly Rs. 305 crores) in the first quarter of this year, according to documents filed for its IPO.
James Park, Fitbit's chief executive and co-founder told CNBC television he was "really excited" about the company's prospects and was not troubled by the launch of the Apple Watch.
"There's over $200 billion in consumer spending on health and fitness every year, this is a massive market," he said.
"There is room for more than one dominant player...the brand Fitbit is really synonymous with health and fitness tracking, so we feel that we have a really significant competitive differentiator on the market."
Catch the latest from the Consumer Electronics Show on Gadgets 360, at our CES 2026 hub.