Indian stocks closed lower for a fifth straight day Monday with the 30-scrip sensitive index Sensex of the S&P Bombay Stock Exchange shedding 175.19 points or 0.85 percent to close at 20,490.96. The Sensex opened at 20,596.40 and touched a high of 20,672.53 and a low of 20,453.15. The wider 50-scrip Nifty of the National Stock Exchange also closed lower at 6.078.80 points, down 61.95 points or 1.01 percent.