U.S. stocks were mixed on Thursday as investors remained cautious ahead of the jobs report on Friday and next Tuesday's presidential election. The S&P 500 could narrowly snap a seven-day losing streak, its longest in five years. Services activity in the U.S. weakened in October, though remained in expansionary territory for its 81st straight month. New orders and business activity both softened, according to the non-manufacturing ISM index. Chesapeake Energy (CHK) - Get Report rallied after reporting surprise quarterly adjusted profit, its first in the green in six quarters. Lower costs helped to offset a 32% slump in revenue. Mobile-game developer Zynga (ZNGA) - Get Report reported a surprise loss over its third quarter as average monthly active users declined. Fourth-quarter revenue guidance also fell short of estimates.