The Sensex at the Bombay Stock Exchange tumbled 291 points, or 1.5 percent, to close below the 19,000 mark, at 18,862, today, after the presentation of the Union Budget, and amid the monthly derivatives expiry. The Nifty at the National Stock Exchange slumped 104 points, or 1.8 percent, to 5,693.But stock markets Japan, China, Hong Kong, South Korea and Singapore rose between 0.3 percent and 2.7 percent.