The Sensex at the Bombay Stock Exchange fell 49 points, or 0.3 per cent, to 15,890, in early trade, today, as investors booked profits after a two-session rally.Later, after moving in and out of the positive zone, in volatile trade, the Sensex stood 57 points, or 0.4 percent in positive territory, at 15,997 in afternoon deals.The 30-share Sensex had gained more than 480 points in the past two trading sessions.Other Asian markets in Japan, China, Hong Kong, South Korea, Singapore, and Taiwan were trading mixed, today. But over on Wall Street, the Dow Jones Industrial Average had jumped 1.5 per cent, overnight.