The BSE benchmark Sensex bounced back by 191 points to regain the psychological 20,000 points level in opening trade on Thursday. The 30-share index rose to trade at 20,056 points in opening trade.Similarly, the wide-based National Stock Exchange Nifty index moved up by 87.50 points to 6,076. Brokers said fresh foreign capital inflows into equities and a firming trend in global markets helped shares of Indian blue-chip companies rebound.In Asia, Hong Kong's Hang Seng Index was up by 1.06 per cent and Japan's Nikkei Index by 0.61 per cent in early trade. In the US, the Dow Jones Industrial Index ended a shade lower on Wednesday.