A late burst of buying left US stock indexes higher at the closing bell after a day of wavering between small gains and losses. Oil stocks did well Monday after the price of crude shook off a long string of losses and turned higher. Chevron rose 3% and Exxon Mobil gained 2%, the most in the Dow Jones industrial average. Natural gas prices sank to their lowest level since September 2001; traders are blaming unusually warm winter weather in the US, as natural gas is commonly used to heat homes. The Dow rose 103 points, or 0.6%, to 17,368. The Standard & Poor's 500 index climbed nine points, or 0.5%, to 2,021. The Nasdaq composite rose 18 points, or 0.4%, to 4,952. (More NYSE stories.)