The Sensex at the Bombay Stock Exchange opened 74 points, or 0.5 per cent higher, at 16,227, today. But the Sensex later surrendered all its gains, and stood 65 points, or 0.4 per cent in the red, at 16,087, a short while ago.Stock markets in China, Hong Kong, Singapore and South Korea were closed today for the Lunar New Year holiday. Japan's Nikkei index fell 0.8 percent.