Recovering smartly from initial losses, the Sensex at the Bombay Stock Exchange ended with a small gain of 28 points, or 0.2 percent, at 17,996, on wednesday, even as the rupee hit a lifetime low against the dollar, and as global markets lost ground. But the Nifty at the National Stock Exchange closed with a marginal loss of 2 points, at 5,285.Stock markets in Japan, China, Hong Kong, South Korea and Singapore declined between 0.1 percent and 1.5 percent.