The Sensex at the Bombay Stock Exchange rose 57 points, or 0.3 per cent, to 16,222 in opening trade, on Wednesday morning, on sustained buying by investors, after Moody's upgrade of the country's short-term foreign currency bank deposits, and on hopes of a rate cut by the Reserve Bank. But later, the market turned volatile, and after moving in and out of the positive zone, the Sensex stood just 27 points, or 0.2 percent in positive territory, at 16,192 in afternoon deals, a short while ago.Other regional bourses in Japan, China, Hong Kong, Singapore, Indonesia and South Korea were trading mixed, today, as optimism about the US economy offset a warning from Fitch Ratings that it may downgrade Italy's credit rating. Across on Wall Street, the Dow Jones Industrial Average had gained 0.6 per cent, overnight.