Lifted by a firm trend in the regional bourses, the Sensex at the Bombay Stock Exchange opened 124 points higher, at 18,452, this morning. But the Sensex later erased all its early gains, to stand as much as 203 points, or 1.1 percent in the red, at 18,125, in volatile trade, a short while ago, as macro-economic concerns continued to hurt investor sentiment. The benchmark index has lost 825 points in the past four trading sessions.Other Asian markets in Japan, China, Hong Kong, Indonesia, Singapore and South Korea were up by between 0.1 percent and 0.8 percent, today, after strong US factory data, and surging commodities prices offset fears that the unrest in Egypt could spread to other parts of the Middle East. The US Dow Jones Industrial average had gained 0.6 per cent, overnight.