Key equity indices see-sawed between gains and losses on Wednesday and closed in the red zone as investors turned cautious over the sustainability of a recent risk rally. At the closing bell, the BSE SandP Sensex was down by 20 points or 0.04 per cent at 51,309 while the Nifty 50 edged lower by 3 points or 0.02 per cent to 15,107. Sectoral indices at the National Stock Exchange were mixed with Nifty private bank down by 0.7 per cent, financial service by 0.2 per cent and metal by 0.8 per cent. But Nifty realty gained by 1.6 per cent and auto by 0.9 per cent. Among stocks, HDFC Bank dropped by 1.2 per cent to close at Rs 1,591.90 per share. Axis Bank closed 0.7 per cent lower and IndusInd Bank by 0.4 per cent. Tata Steel lost by 1.1 per cent a day after the company reported a consolidated profit of Rs 3,989 crore for the quarter ended December 2020 driven by improved realisation-backed strong operating income.