U.S. stocks edged higher on Thursday, with LinkedIn one of the few standouts in an otherwise lackluster session as its shares doubled in their trading debut.

The S&P 500 ran into resistance after its recent bounce, and many investors have resigned themselves to a patch of economic weakness over the summer.

While stocks have been resilient, only falling 1.5 percent, the S&P is struggling to make headway above 1,340, an area that has met with repeated bouts of selling.

Now on the way back up, just as far as the next few days are concerned, I think that 1,340 could stop the short-term bounce, said Ari Wald, equity strategist at Brown Brothers Harriman in New York.

He said 1,360 on the S&P 500 is a more significant resistance level that coincides with a 76.4 percent retracement of the index's slide from its all-time high to the bear market low in March 2009. The S&P could struggle to break that level due to low trading volume, said Wald.

We have seen very low volume on the upside and also marginally higher volume on the downside, which is also concerning, he said.

Economic data painted a cloudy picture as slowing factory activity in the mid-Atlantic region and falling sales of existing homes offset a drop in weekly jobless claims that suggested the labor market was on track for recovery.

My bottom line, at least over the summer, is I that think there is enough valuation cushion to withstand a slowing of economic growth, so I think we have a cyclical slowing priced in, said Jack Ablin, chief investment officer, Harris Private Bank in Chicago.

Shares of LinkedIn Corp , the social network company, more than doubled their IPO price in a jump reminiscent of the heyday of investors' love affair with Internet stocks.

LinkedIn rocketed to an intraday high of $121.97 -- as much as 171 percent above its initial offering price of $45. The shares closed at $94.25, up 110 percent.

The Dow Jones industrial average <.DJI> gained 45.14 points, or 0.36 percent, to 12,605.32. The Standard & Poor's 500 Index <.SPX> rose 2.92 points, or 0.22 percent, to 1,343.60. The Nasdaq Composite Index <.IXIC> added 8.31 points, or 0.30 percent, to 2,823.31.

Wald said he is looking for a correction back to as much as 1,230 on the S&P 500 over the summer, a seasonally weak period for equities.

Investors have been rotating into defensive areas of the market, such as healthcare and utilities, which are less sensitive to market weakness.

Semiconductor shares fell after Goldman Sachs cut its rating on Intel Corp , citing slowing processor shipments, rising competition and record capital expenditure levels this year. The firm also lowered its rating on Applied Materials as part of a wider downgrade on the semiconductor equipment sector.

Intel shares lost 1.4 percent to $23.54 and Applied Materials dropped 1.2 percent to $14.33. The PHLX semiconductor index <.SOX> declined 0.9 percent.

Stocks, bonds, gold and the euro are expected to fall in the three months after the upcoming end of the Fed's second massive bond-buying operation, also known as quantitative easing, or QE2, a Reuters poll of 64 analysts and fund managers found on Thursday.

About 6.2 billion shares were traded on Thursday on the New York Stock Exchange, NYSE Amex and Nasdaq, compared with the average of about 8.4 billion last year.

Advancing stocks outnumbered declining ones on the NYSE by almost 3 to 2, and on the Nasdaq, the ratio was about even.

(Editing by Theodore d'Afflisio and Leslie Adler)

Intel