U.S. stocks fell on Thursday after three days of gains as earnings from JPMorgan and soft economic data from China reinforced worries about a slowing global economy.

With the S&P 500 rising six out of the last seven sessions, the index has run up 11.4 percent from an intraday low hit last Tuesday, adding to concerns the rally was overdone.

The S&P has had its largest seven-day gain since March 2009 on growing optimism that European leaders were making progress in tackling the region's debt problems.

We've had a pretty decent rally from the nadir, but we can't continue to go straight up in the absence of anything definite from Europe, said Mark Luschini, chief investment strategist at Janney Montgomery Scott in Philadelphia. We've been rising on hope rather than anything tangible.

China's trade surplus narrowed for a second straight month in September as both imports and exports were lower than expected, pointing to cooling domestic and global economic demand.

According to a Reuters poll, analysts have reined in their expectations for U.S. economic growth, though it is still expected to pick up a notch by year-end.

JPMorgan Chase & Co , the second-largest U.S. bank, slid 6.5 percent to $31.05 and was the biggest drag on the Dow after reporting a drop in its third-quarter net profit.

The first major U.S. bank to report earnings said profits were hurt as the European debt crisis pushed investment banking clients to the sidelines. The KBW Bank index <.BKX> shed 4.2 percent while Bank of America Corp lost 6.1 percent to $6.18.

We saw some fairly material weakness in capital markets and JPMorgan's banking operations, and I would expect those trends to be repeated, no matter what bank you're looking at, said Paul Larson, chief equities strategist at Morningstar in Chicago.

The Dow Jones industrial average <.DJI> dropped 114.28 points, or 0.99 percent, to 11,404.57. The Standard & Poor's 500 Index <.SPX> fell 13.63 points, or 1.13 percent, to 1,193.62. The Nasdaq Composite Index <.IXIC> slipped 7.11 points, or 0.27 percent, to 2,597.62.

Vertex Pharmaceuticals Inc was the top gainer in the Nasdaq 100 <.NDX>, climbing 8.1 percent to $43.55 after IMS Health said it was revising estimates of the number of prescriptions written in late September for Vertex's hepatitis C drug.

In U.S. economic data, new claims for jobless benefits were little changed last week and the trade deficit narrowed marginally in August, indicating a modest improvement in the economy.

Google will report third-quarter earnings after the close and investors will be looking to see how the slowing economy is impacting its advertising business. Earnings are expected to rise 14.5 percent year-over-year at the Internet company, while revenue is seen up 31.7 percent.

A report on Wednesday that Akamai Technologies Inc was close to being acquired by Google has no merit, a person familiar with the matter said. Akamai shares shot up 5.5 percent to $24.65, and Google rose 0.8 percent to $552.67. [nN1E79B1TA]

(Reporting by Ryan Vlastelica; Editing by Jan Paschal)