New Delhi:  Indian stock markets witnessed a sharp downturn on Friday, with benchmark indices tumbling as widespread selling gripped Dalal Street amid weak investor sentiment. The BSE Sensex dropped approximately 850 points , while the NSE Nifty50 slipped below the 25,550 level , reflecting heightened risk aversion and volatility in the market. Key Market Movements Sensex:  Saw a steep decline with most of the 30 constituent stocks trading in the red. Heavyweights across sect