Stocks took a turn lower in afternoon trading, ending a six-day winning streak, the AP reports. Walmart plunged 10% Tuesday after reporting weak online sales and disappointing earnings. Other retailers and grocery store operators also fell. Target gave up 3% and Ross Stores lost 2.7%. A sell-off in the afternoon wiped out early gains, which were led by technology companies. NXP Semiconductor jumped 6% after Qualcomm raised its offer for the company. The Standard & Poor's 500 index fell 15 points, or 0.6%, to 2,716. The Dow Jones industrial average lost 254 points, or 1%, to 24,964. The Nasdaq composite slipped 5 points, or 0.1%, to 7,234. Bond prices fell. The yield on the 10-year Treasury rose to 2.89%. (More stock market stories.)