The BSE benchmark Sensex rose nearly 179 points in opening trade today. Later it shed some of its gains and was trading at 16587, up by 88 points when reports last came in. The wide-based National Stock Exchange index Nifty climbed 25 points to 4,923 points.Brokers said sentiments on the domestic bourses remained buoyant following market regulator SEBI decision to allow stock exchanges to have separate trading platforms for SMEs and relax the criteria for IPOs and FPOs of all companies. The Hong Kong's Hang Seng index shot up by 1.2 per cent while Japan's Nikkei rose 1.3 per cent in morning trade today.The US Dow Jones Industrial Averaged gained 2.03 per cent yesterday.