The sensex at the Bombay Stock Exchange was trading 31 points in the green at 18,491 in late morning deals a short while ago. Earlier the Sensex rose by 64 points to 18,534 in early trade on sustained buying by funds and retailers largely on hopes of more reform measures by the government in the Winter Session of Parliament.Meanwhile the Nifty at the National Stock Exchange also stood one point in positive territory at 5,616.