Shares in social networking website LinkedIn more than doubled on their trading debut in New York on Thursday, having been priced at $US45 each.
The share price reached $US122 at one point in the sort of debut rally not seen since the dotcom bubble of the late 1990s.
The initial sale price was already at the top of an increased range.
LinkedIn sold 7.84 million shares at $US45 each. At $100 per share, the company is worth about $US10 billion.
The BBC reports LinkedIn is the first US social network site to get a share listing.
Some analysts believe its strong debut is down to over-enthusiasm by investors for social media stocks.
Facebook and Twitter are both expected to seek stock market listings in the next few years.
LinkedIn shares closed at $94.25 on the New York Stock Exchange.