Shares of LinkedIn stock traded at double their initial offering of $45 in the first hour after the business social network launched its initial public offering today, CNNMoney.com reported. At $90 a share, LinkedIn was valued at $8.5 billion. The offering has netted the company more than $350 million, making it one of the largest tech IPOs since Google Inc. in 2004. LinkedIn began trading on the New York Stock Exchange under the ticker symbol “LNKD.” The company raised its offering range earlier this week to $42 to $45 a share from $32 to $35 a share. In an updated SEC filing, LinkedIn said it turned a profit of $2.1 million on revenue of $93.9 million in the first quarter. In 2010, the company’s last full fiscal year, it earned $15 million in profit on sales of $243 million.