At close, the Sensex was down 136.69 points or 0.26% at 52,793.62, and the Nifty was down 25.80 points or 0.16% at 15,782.20 for the sixth straight day despite an upbeat global mood., as the investors booked profit in banks and metal stocks.SBI was the biggest laggard on the index, down nearly 5 percent, as the lender's Q4 missed Street's estimates.NTPC, ICICI Bank, Axis Bank, Maruti Suzuki, Airtel, HDFC twins, and Bajaj twins were the other draggers. Gainers included Tata Motors, Sun Pharma, M&M, ITC, and HUL. The BSE SmallCap index added over 1.3 percent and the BSE MidCap index gained 0.6 percent. Sectorally, the Nifty Metal index fell 2 percent, followed by the Nifty Bank index (down over 1 percent). On the upside, the Nifty Auto index gained 2.5 percent