Erasing all its early gains, the Sensex at the Bombay Stock Exchange dropped 182 points, or 1 percent, to close below the 19,000 level, at 18,969, on Tuesday, after the Reserve Bank hiked its key policy rates, and revised upwards its inflation forecast. The Nifty at the National Stock Exchange shed 56 points, or 1 percent, to 5,687. Stock markets in Japan, China, Hong Kong, Singapore and South Korea again ended on a mixed note.