The Sensex at the Bombay Stock Exchange, which rallied by 269 points in opening trade today, lost ground in the late morning deals and was trading 26 points in the positive territory at 17,529 when reports last came in. After gaining nearly 357 points in the previous session, the 30-share index rose by 269 points, or 1.54 per cent, to 17,772 in opening trade today, due to the cash reserve ratio cut by the Reserve Bank of India, RBI on Friday.In a similar fashion, the broad-based National Stock Exchange Nifty index was trading 5 points in the green at 5,339.