Stocks Log First Weekly Loss Since Early May

Trading was also jumpy because of the occurrence of a quarterly "quadruple witching," which marks the simultaneous expiration of four different kinds options and futures contracts.

The Dow Jones industrial average fell 15.87, or 0.2 percent, to 8,539.73, with 16 of the 30 stocks that make up the average posting losses. The broader Standard & Poor's 500 index rose 2.86, or 0.3 percent, to 921.23 and the Nasdaq composite index gained 19.75, or 1.1 percent, to 1,827.47.

About three stocks rose for every two that fell on the New York Stock Exchange, where consolidated volume came to a heavy 5.47 billion shares, compared with 4.58 billion shares the day before.

All the major indexes closed the week down for the first time since the week of May 11. The Dow lost 3 percent, the S&P 500 index fell 2.6 percent, and the Nasdaq shed 1.7 percent.

Stocks tumbled early in the week as a handful of weak economic reports, including news of a seventh straight monthly drop in industrial production, bucked sharply with the gradual improvement traders had grown used to with other economic readings.

Stocks rebounded modestly on Thursday, spurred by a series of better data on economic activity, including a report that showed the overall number of people drawing unemployment benefits fell last week for the first time since early January.