At noon on Tuesday, the core equity indices i.e., Sensex and Nifty 50 were seen trading on the greener side. The Sensex was at 57,297.66, up by 891.82 points or 1.58 per cent, while Nifty was at 17,103.95 up by 260.10 points or 1.54 per cent from the last trading session.