The BSE benchmark Sensex gained over 63 points in opening trade today. The Sensex was trading at 17490, up by over 27 points a short while ago.Marketmen said bargain buying at selective counters by funds and retail investors and gains in other Asian markets helped the domestic equity market to stage a moderate comeback.In the Asian region, Hong Kong's Hang Seng was up by 0.43 per cent in early trade today, while Japan's Nikkei was closed for a public holiday.The US Dow Jones Industrial average ended 0. 09 per cent lower in yesterday's trade.