Zoom Video Communications Inc. soared in its trading debut to more than 16 times its last private valuation and making a billionaire of its founder. Shares of the San-Jose based video-conferencing service opened at $65 each, after Zoom sold 20.9 million shares Wednesday to raise $751 million in its U.S. initial public offering—the fourth-biggest of the year. Zoom, which rose as much as 83 percent above its IPO price, was up 76 percent to $63.20 at 1:38 p.m. in New York, valuing the company at $16.2 billion.