A sharp fall in the equity market made investors poorer by Rs 5.29 lakh crore on Tuesday when the BSE benchmark Sensex tumbled over 800 points.A host of negative triggers -- muted quarterly earnings, continuous foreign fund outflows and weak trends in Asian and European markets -- dragged the benchmark indices lower.The BSE benchmark gauge tumbled 820.97 points or 1.03 per cent to settle at 78,675.18.