The Sensex at the Bombay Stock Exchange lost 37 points, or 0.2 per cent, to 18,525 in opening trade on Monday morning, on investor caution, in line with falling Asian markets. After briefly recovering to gain 61 points, at one stage, the Sensex once again lost ground, and stood 62 points, or 0.3 percent in negative territory, 18,500, in volatile trade, a short while ago. Other Asian markets in China, Hong Kong, Singapore, South Korea and Taiwan were down by between 0.1 percent and 0.4 percent on Monday, as US and European debt concerns kept investors wary.