Domestic benchmark equity indices, Sensex and Nifty, plunged over one per cent today due to a sell-off in banking, financial, and IT stocks, as caution prevailed among investors ahead of the US presidential election and the Federal Reserve’s monetary policy meeting this week. The 30-share BSE Sensex tanked 1,227 points, or 1.54 per cent, to 78,497 points, while the NSE Nifty50 declined 420 points, or 1.73 per cent, falling below the 24,000 level to 23,884 points when the reports last came in.