Social networking site Facebook's initial public offering opened for trading at $42.05 at a $4 premium per share on Nasdaq on Friday. Eighty million shares were traded in the first 30 seconds.
Wearing his trademark hoodie, Mark Zuckerberg, the social networking site's founder, rang the bell remotely from the company headquarters in Menlo Park, California, flanked by chief operating officer Sheryl Sandberg and other employees.
Zuckerberg, 28, is himself selling shares worth $1.2 billion (at $38 a share). That will be cash in hand.
His personal worth, however, will be $19.1 billion, just a little short of India's richest man, Mukesh Ambani, who, according to Bloomberg's daily index of billionaires, was worth $19.8 billion on Friday.
The $104-billion, eight-year-old company, its executives and early investors are together selling 484.4 million shares in the IPO, expecting to raise $18.4 billion at the initial price of $38 a share.
The share shot to $43 and then settled down to a lower figure which, some analysts said, was not something they had expected to see on the opening day given the preceding frenzy.
"It is a historic moment, and a bit personal for all of us, since we were early users back in 2004 and have been daily users of the product since then," said Akshay Kothari, co-founder of Pulse news application.