Stocks had their biggest gain in four weeks as investors were encouraged by corporate deal news. The Dow Jones industrial average gained 244 points, or 1.4%, to 17,737 Wednesday. The Standard & Poor's 500 rose 33 points, or 1.6%, to 2,083. The Nasdaq composite increased 89 points, or 1.8%, to 5,075.
ConAgra Foods jumped 4% Wednesday. The company is spinning off its frozen potatoes business. Norfolk Southern climbed 6% after receiving an unsolicited offer to be bought out by Canadian Pacific. Bank stocks rose after minutes from the latest Federal Reserve meeting suggested the bank was ready to raise interest rates next month. Banks can charge more to loan money when rates are higher. JPMorgan Chase and Bank of America rose 2%. (Read more Dow Jones stories.)