U.S. stocks rose on Thursday, with the S&P 500 topping the 1,400-mark for the first time since the financial crisis on a strong run of economic data.

Though 1,400 on the S&P, which marks the highest level for the index since June 2008, does not have much technical importance, it is viewed as a bullish psychological marker.

Trading was also volatile at the start of quadruple witching, the dates of expiration and settlement of four types of equity futures and options contracts.

The S&P 500 has risen more than 11 percent so far this year without a major pullback, and while some have called for a consolidation, others see the momentum persisting.

We've had such a strong run that a lot of people are concerned we're up too much, but data has been so positive that I think we'll continue to grind higher, said Hank Herrmann, chief executive of Waddell & Reed Financial Inc in Overland Park, Kansas.

Herrmann, who helps oversee $90 billion in assets, forecast further gains of as much as 8 percent in the S&P until the U.S. presidential election in November.

On Thursday, U.S. Labor Department data showed new claims for unemployment benefits fell back to a four-year low last week, and producer prices, excluding food and energy, were contained.

Manufacturing data in New York and the U.S. mid-Atlantic region also improved, according to regional Federal Reserve surveys.

The Dow Jones industrial average <.DJI> was up 32.39 points, or 0.25 percent, at 13,226.49. The Standard & Poor's 500 Index <.SPX> was up 6.38 points, or 0.46 percent, at 1,400.66. The Nasdaq Composite Index <.IXIC> was up 12.45 points, or 0.41 percent, at 3,053.18.

The S&P 500 snapped a five-day winning streak on Wednesday as investors found little reason to extend a rally that took the benchmark index to four-year highs. But the index is up over 2 percent this week, its best since early February.

Apple Inc pulled back 1.1 percent to $582.89, ending a six-day streak of gains, though it hit a new all-time high above $600 in early trading. Some analysts have predicted the stock will move to $700 within 12 months.

Helping transport stocks but hurting energy companies was Britain's decision to cooperate with the United States in a bilateral agreement to release strategic oil stocks in an effort to prevent high fuel prices derailing economic growth in a U.S. election year, according to two British sources.

Brent crude futures fell 1 percent. The Dow transport index <.DJT> rose 3.2 percent, while the S&P energy index traded flat.

Semiconductors moved higher, led by Advanced Micro Devices Inc , which jumped 5.7 percent to $8.20 after Jefferies upgraded the stock to buy. The Philadelphia Semiconductor Index <.SOX> gained 1.4 percent.

Ross Stores Inc reported a higher profit for the holiday quarter as shoppers sought out popular clothing brands at discount prices, and the off-price chain forecast respectable sales and profit gains for this fiscal year. Shares dropped 0.5 percent to $55.26. The Morgan Stanley retail index <.MVR> rose 0.4 percent.

Three initial public offerings made their debuts on Thursday: cloud computing-based software company Demandware Inc , analog chipmaker M/A-Com Technology Solutions Holdings and Allison Transmission Holdings .

Demandware surged 53 percent to $24.59, M/A-Com advanced 10.5 percent to $21 and Allison Transmission rose 1.5 percent to $23.35.

(Editing by Padraic Cassidy)