The BSE benchmark Sensex today tumbled by 455 points to close below key 20000-mark, wiping off Rs 1.1 lakh crore in investor wealth, on panic selling in realty, banks and PSUs as hopes of rate cut crashed after RBI comments amid GDP growth slumping to decade-low of 5 per cent.

The 30-share barometer, after gaining 68 points in the previous session, tumbled 455.10 points, or 2.25 per cent to 19,760.30. This is its biggest daily loss since March 2012.

Similarly, the NSE index Nifty plunged by 138.10 points, or 2.26 percent to 5,985.95.

Belying hopes of further rate cuts, the Reserve Bank Governor D Subbarao's comments that there are still upside risks to inflation spooked stock markets. Additionally, RBI's concern about widening country's current account deficit amid rupee falling to over 10-month lows, also put pressure.