The biggest Internet IPO since Google combined with a drop in oil prices to send the broad stock market higher.
Shares of social networking company LinkedIn jumped 109 percent to $94.25 on the first day they began trading on the New York Stock Exchange under the ticker symbol "LNKD." The debut is seen as a preview of other social networking sites that are expected to start trading during the next year. The list of candidates includes the online messaging service Twitter, game maker Zynga, and the biggest social network of all, Facebook.
"LinkedIn represents the first opportunity for the average investor to participate in what looks like a lasting, powerful trend of social media," said Lawrence Creatura, a portfolio manager at Federated Investors. "They're frothy with excitement, and that's being imputed into the share price."
LinkedIn finished the day with a gigantic price-to-earnings ratio of 554, a valuation reminiscent of Internet stocks during the late 1990s tech bubble. By comparison, the average price-to-earnings ratio of technology companies in the S&P 500 index like Apple Inc. and Google Inc. is 15.
Sumeet Jain, a principal with venture investing firm CMEA Capital, said LinkedIn's IPO suggests that the number of mergers and acquisitions will increase this year as social networking companies grow, a potential boon for the stock market.
LinkedIn is "going to have to be quite aggressive" to meet investors' lofty expectations, Jain said. "All the rest of the companies in the pipeline, when they're all public companies they will be extraordinarily active acquirers as well."
The Dow Jones industrial average rose 45.14, or 0.4 percent, to close at 12,605.32. The S&P 500 gained 2.92, or 0.2 percent, to 1,343.60. The Nasdaq composite index rose 8.31, or 0.3 percent, to 2,823.31.
Oil prices fell back below $100 a barrel after an international agency said there is an "urgent need" for refineries to produce more gasoline and bring down pump prices in order to prevent a downturn in the global economy. Delta Air Lines Inc. rose 4.1 percent and JetBlue Airways Corp. rose 1.4 percent on expectations that their fuel costs would decrease.
Oil prices have fallen about 13 percent since the beginning of May as part of a broad-sell off in commodities due to fears that the economy is slowing. Despite LinkedIn's gains, concerns about the economy weighed on the market again Thursday.
The National Association of Realtors said fewer people purchased previously occupied homes in April. The Conference Board's outlook for future economic activity decreased for the first time since June 2010. And the Philadelphia Federal Reserve said that its measure of manufacturing activity slumped to its lowest reading since October.
The mixed news confirmed investors' belief that economic growth could be slow in the coming months. The yield on the benchmark 10-year Treasury note had risen as high as 3.24 percent following the positive jobs news but was back down to 3.17 percent, just below the rate it was trading at late Wednesday. Bond yields tend to rise when investors anticipate stronger economic growth.
"The fact that yields are still up today, even after this relatively weak set of data, tells me that people have factored in" expectations that the economy will grow more slowly this quarter, said Paul Zemsky, chief investment officer of multi-asset strategies for ING Investment Management.
With little fresh economic or corporate data expected in the next two weeks, the market will be "pretty much trading sideways unless something happens to throw people for a loop again," Zemsky said.
Stocks opened higher after the Department of Labor reported that applications for unemployment dropped more than expected. Indexes gave up those early gains after three negative reports on the economy came out at midmorning.
In a sign that the U.S. consumer recovery remains uneven, Big Lots Inc. fell nearly 11 percent after news reports that it decided not to sell itself. The Wall Street Journal said late Wednesday that the company received bids from two private-equity groups that were lower than it had hoped.
Sears Holding Corp. reported softer sales at its Kmart and Sears stores, causing a first-quarter loss of $1.58 per share, worse than analysts expected. The stock fell 2.6 percent.
Two stocks rose for every one that fell on the New York Stock Exchange. Consolidated volume came to 3.3 billion shares.