The BSE benchmark Sensex is trading 17 points up at 21,181 in afternoon deals. Earlier, it gained 59 points in morning trade on the back of persistent buying in realty, banking, auto and capital goods shares, triggered by sustained foreign inflows into the equity market. The 30-share index opened up at 21,158 and firmed up to hit an all-time high at 21,293 before quoting at 21,219 showing a rise of 54.63 points from its last close. The Sensex surpassed its previous record high of 21,206.77 touched on January 10, 2008.The NSE 50-share Nifty also moved up by 4 points to 6,303.