Domestic stock markets started Monday's session on a lower note, extending their losses to a second straight day, amid weakness in global peers. The S&P BSE Sensex index fell as much as 435.23 points to 39,078.16 in early trade, and the NSE Nifty benchmark moved to 11,682.90, down 128.25 points from the previous close. Weakness across sectors, led by auto, banking and energy shares, dragged the markets lower. With Budget presentation now behind, the focus will shift to macroeconomic data due this week for market cues, according to analysts.