Falling for the third straight session, the Sensex at the Bombay Stock Exchange ended with a small loss of 19 points, or 0.1 percent, at 17,214, today, on investor caution, amid poor exports numbers. The Nifty at the National Stock Exchange shed 8 points, or 0.2 percent, to 5,227.But stock markets in Japan, Hong Kong, South Korea and Singapore rose between 0.1 percent and 1.5 percent.