Benchmark equity indices snapped their two-day gaining streak after selling in metal and banking stocks amid weak trends in global markets and SEBI warning over midcap-smallcap rally. The BSE Sensex declined by 616.75 points or 0.83 per cent to settle at 73,502.64. The broader NSE Nifty slumped by 160.90 points or 0.72 per cent to close at 22,332.65.