The BSE benchmark Sensex dived nearly 531 points to close at 48,348 on Monday, prolonging its losing streak to the third straight session, weighed down by massive selling particularly in energy and IT stocks. After swinging nearly 1,000 points during the session, the BSE benchmark settled with a loss of 530.95 points or 1.09 per cent at 48,347.59. Likewise, the NSE gauge Nifty plunged 133 points or 0.93 per cent to end the session at 14,238.90.