(Newser) – Stocks are ending mostly lower, led by another drop in materials and energy companies as worries about global growth continue. The Dow Jones industrial average declined 51 points, or 0.3%, to 16,279 today. The Standard & Poor's 500 index gave up four points, or 0.2%, to 1,938. The Nasdaq composite also fell four points, or 0.1%, to 4,752. Investors are worried that more signs of weakness in China will mean soft demand for basic materials and energy. Dow Chemical and Chevron each fell 2%. The price of oil plunged 4% to $44.48 a barrel New York. That followed a 2% slump the day before. Bond prices fell. The yield on the benchmark 10-year Treasury note rose to 2.15%.