Stocks accelerated their losses in the final minutes of trading to close near session lows Thursday, pushing the S&P 500 below the key 1,400 level, a day ahead of the Fed's Jackson Hole meeting and following reports that Spain may delay its decision on seeking a bailout.
The Dow Jones Industrial Average tumbled 106.77 points, or 0.81 percent, to 13,000.71, led by Intel and Caterpillar . The blue-chip index dipped below the psychologically-important 13,000 level several times throughout the session.
The S&P 500 fell 11.01 points, or 0.78 percent, to close at 1,399.48, finishing below the 1,400 level for the first time since August 6. The Nasdaq dropped 32.48 points, or 1.05 percent, to end at 3,048.71.
The CBOE Volatility Index, widely considered the best gauge of fear in the market, jumped to close near 18.
All key S&P sectors ended lower, led by industrials and techs. All three major indexes are now lower for the week and the Dow is in negative territory for the month.
Stocks took another leg lower following a report that Spain will delay deciding whether to seek a sovereign bailout until the aid conditions are clear, according to Prime Minister Mariano Rajoy after a meeting with French President Francois Hollande.
Meanwhile, Slovakia's Prime Minister Robert Fico said there is a 50-percent chance of the currency bloc breaking up, ahead of a series of meetings of leaders next month.
“When you have such a thin market and volume’s so anemic, it doesn’t take much to push things around,” said Joe Saluzzi, co-manager of trading at Themis.
The euro erased its gainsto fall near session lows against the U.S. dollar. European shares also slumpedfollowing the report.
Investors were also cautious a day ahead of Chairman Ben Bernanke’s speech on Friday at the annual symposium in Jackson Hole, Wyoming.
“People’s expectations have been dialed down and they’re not expecting much from Jackson Hole,” said Thomas Lee, chief U.S. equity strategist at JPMorgan on CNBC's "Squawk on the Street." “This has been a thinly-traded market, people are underinvested and we’re seeing some better data...and you’ve got an open window into Election Day before the fiscal cliff becomes prominent. I think the market probably rallies if nothing happens.”
On the economic front, jobless claims was unchanged last week, holding at a seasonally adjusted 374,000, according to the Labor Department. Economists polled by Reuters had forecast claims dipping to 370,000 last week. The four-week moving average for new claims rose 1,500 to 370,250.
Consumer spending gained 0.4 percent in July, climbing by the most in five months, according to the Commerce Department. Meanwhile, income increased 0.3 percent.
Costco and Limited Brands advanced after both retailers topped same-store sales expectationsin August.
Among earnings, Pandora surged after the Internet radio company posted earnings that topped expectations and boosted its current-quarter revenue outlook. At least three brokerages raised their rating on the company to "buy" from "hold."
Apparel store Zumiez is slated to post results after the closing bell.
Sears Holdings will lose its place in the S&P 500 index after the close of trading next Tuesday because the stock’s public float has been below the 50 percent of the index requirement “for an extended period of time.” Sears will be replaced by chemical maker LyondellBasell .
Amazon.com said it has sold out of its Kindle Fire device, which now accounts for 22 percent of all U.S. tablet sales. Amazon did not disclose how many units have been sold or when the gadget will be back in stock.
The Carlyle Group said it will acquire DuPont's performance coatings unit for $4.9 billionand will also take on $250 million of DuPont's unfunded pension liabilities.
Treasury prices extended their gainsafter the government auctioned $29 billion in 7-year notes at high yield of 1.081 percent and bid-to-cover of 2.80.
—By CNBC’s JeeYeon Park (Follow JeeYeon on Twitter: @JeeYeonParkCNBC)
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FRIDAY: Chicago PMI, consumer sentiment, factory orders, farm prices, Bernanke's Jackson Hole speech
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