Standard & Poor's 500 index

Precision Castparts soared 19 percent Monday after Warren Buffett's Berkshire Hathaway said it would buy the maker of industrial components for $32 billion.

Stocks rose in China after weak trade figures led investors to hope for new economic stimulus measures from the Chinese government.

The Dow gained 155 points, or 0.9 percent, to 17,527 as of 9:35 a.m. Eastern time.

Oil prices fell, dragging energy stocks lower.

KEEPING SCORE: The Standard & Poor's 500 index was up nine points, or 0.4 percent, to 2,102 as of 3 p.m. Eastern time. The Dow Jones industrial average edged up four points, less than 0.1 percent, to 17,555, while the Nasdaq rose 41 points, or 0.8 percent, to 5,147.

KEEPING SCORE: The Dow Jones industrial average rose 25 points, or 0.1 percent, to 17,656 as of 9:50 a.m. Eastern. The Standard & Poor's 500 index rose three points, or 0.1 percent, to 2,096 and the Nasdaq composite rose a point to 5,089.

The losses on Friday gave the Standard & Poor's 500 index its fourth losing week out of the last five.