In the earlier trends, market benchmark Sensex slumped over 200 points in opening session on Saturday ahead of the release of the Union Budget to be presented by Finance Minister Nirmala Sitharaman later in the day. After shedding 279 points in early trade, the 30-share BSE index was trading 124.96 points or 0.31 per cent lower at 40,598.53, and the broader NSE slipped 23.10 points, or 0.19 per cent, to 11,939.