LinkedIn Corp. the largest professional networking website, twice got profit on its first trading day which is sheer evidence of surging demand for social media stock and a comeback in business enterprise backed early public offerings. The stock, trading under the symbol LNKD, gained $49.25 , or 109 percent, to $94.25 yesterday after earlier profiting to as high as $122.70 on the New York Stock Exchange.

LinkedIn finished the day with a market value of $8.91 billion, or about 24 times 2011 income, presumptuous first-quarter sales are matched the rest of the year. Facebook Inc., the world’s largest social network, would be valued at about $95 billion using the same multiple. The gains signify well for other Internet businesses that have put off going public while sharpening efforts to make money, and they may brighten forecast for the venture capital .

LinkedIn’s debut replicates a comeback in IPOs for startups funded by venture capitalists. U.S. backed businesses raised $1.38 billion in IPOs in the first quarter, a 47 percent increase from a year earlier, according to the National Venture Capital Association (NVCA. In the first quarter of 2009 there were no venture-backed IPOs. LinkedIn’s presentation is evocative of some of hottest stocks in the dot-com boom.