The Sensex today zoomed over 473 points, biggest single day gain in four months to 18,202 points, as investors bought sound stocks at lower levels despite capital outflows. A slew of positives like easing inflation, market regulator Sebi's decision to probe the recent downslide in stock markets and strong global cues in view of Egyptian President Hosni Mubarak's decision to step down helped boost investor sentiment. Marketmen said that fall in global crude oil prices prompted operators as well as speculators to cover their short positions. The sentiment was so positive that all the 13 sectoral indices ended with sharp to moderate gains of between 5.26 per cent and 0.97 per cent, with capital goods leading the pack. The recently battered interest-rate sensitive stocks from auto, consumer durables, banking and realty sectors followed the suit. Metal and power shares also attracted good buying support. Similarly, the NSE 50-issue also spurted by 146 points to end at 5,456 points.