Indian stock indices, S&P BSE Sensex and Nifty50, fell by over 500 and 150 points, respectively, amid profit booking across sectors with bank and financial services sectors bearing the worst brunt on Wednesday. The market breadth was skewed in favour of bears, with 1,840 declines and 1,625 advances on BSE. Concerns about China's stuttering economic recovery and weak factory activity data, contributed to losses, accompanied by technical factors and lacklustre global markets. The losses came after four consecutive days of rallies that brought Sensex and Nifty close to their all-time highs. MSCI rebalancing will also come into effect, leading to inflows into stocks.