The Sensex at the Bombay Stock Exchange, which had opened 57 points higher, this morning, later gathered further steam, to gain more than 300 points at one stage, and then stand a good 283 points, or 1.6 percent in the positive zone, at 18,374, in afternoon deals, a short while ago. The domestic market rose on bargain hunting by investors. Elsewhere, Japan's main stock index fell 0.3 percent. But other key Asian markets are mostly closed for the Lunar New Year holiday, today. The US Dow Jones Industrial Average had ended flat, overnight.