The Sensex at the Bombay Stock Exchange ended with a slim gain of 20 points, or 0.1 per cent, at 15,936, on Monday. The Nifty at the National Stock Exchange rose just 3 points, or 0.1 percent, to 4,760. But stock markets in Japan, China, Hong Kong and South Korea lost between 0.3 percent and 1 per cent. The rupee weakened 6 paise, to 46.80 against the dollar. Gold gained 80 rupees, to 16,520 rupees per ten grams in Delhi.