The Sensex at the Bombay Stock Exchange gained 174 points, or 0.9 percent, to 18,805, on Thursday, on all-round buying interest, after some reassuring words from the Finance Minister, and ahead of the release of some big corporate quarterly results. The Nifty at the National Stock Exchange rose 56 points, or 1 percent, to 5,708.But stock markets in Japan, China, and South Korea lost between 0.6 percent and 0.8 percent.