The Sensex at the Bombay Stock Exchange gained a solid 354 points, or 2.1 percent, to close above the 17,000 mark, at 17,099, amid firm global markets, today. IT stocks shone, on a weakening rupee. The Nifty at the National Stock Exchange surged 108 points, or 2.2 percent, to 5,140.Stock markets in China, Hong Kong, South Korea and Singapore gained between 0.5 percent and 1 percent, ahead of a US central bank meeting.