The Sensex at the Bombay Stock Exchange jumped 311 points, or 1.8 per cent, to 17,456 in early trade, today, on fresh buying by funds and retail investors at lower levels, amid firm global markets. Later, the Sensex remained firm, and stood 331 points, or 1.9 per cent in the positive zone, at 17,476 in afternoon deals, a short while ago. Other Asian markets in Japan, China, Hong Kong, Indonesia, Singapore, South Korea and Taiwan were up by between 0.4 percent and 2 percent, today, after data showed that Chinese inflation cooled slightly, and on optimism about Greece's crucial debt-swap. Over in the US, the Dow Jones Industrial Average had gained 0.6 per cent, overnight.