Fitbit streaked past its initial public offering price in its New York Stock Exchange debut Thursday. Shares began trading under the FIT ticker symbol at $30.40, more than 50 percent above the initial public offering price of $20. The opening price valued the company at about $6.3 billion.

Fitbit closed Thursday at $29.68, up $9.68 from its IPO price, representing a one-day gain of 48.4 percent.

The company had first priced its offering at $14 to $16 per share with a plan to sell 29.9 million shares. This range was raised on Tuesday to $17 to $19, and the number of shares on offer increased to 34.5 million after investors showed strong demand. On Wednesday night, the deal was priced at $20 and the size of the offering was once more increased to 36.6 million.

At the IPO price, Fitbit raised $732 million for itself and its selling stockholders. The IPO price valueD Fitbit at $4.1 billion.

The San Francisco, CA company's 2014 revenue amounted to $745 million as it
sold 10.9 million devices, nearly three times the previous year’s
revenue of $271 million.