Snapping a five-day losing streak fall, the Sensex at the Bombay Stock Exchange shot up 510 points, or 3.4 percent, to 15,685 on Wednesday, as investors picked up blue-chips at lower levels, amid a firm global trend.The Nifty at the National Stock Exchange climbed 149 points, or 3.3 percent, to 4,693.Stock markets in Japan , Hong Kong , Singapore and South Korea rose between 1.5% and 3.1%