U.S. equities were mixed in midday trading Friday, though remained on track to close out with their best monthly gain in four years. Stocks have rallied in October as crude oil recovered from lows, and China and the European Central Bank committed to stimulus to reinvigorate growth. Drugstore chain CVS Health (CVS) led S&P 500 decliners after it guided for weaker-than-expected earnings over fiscal 2016. The company has managed to boost pharmacy sales even as its drugstore business suffers after ceasing all tobacco sales. Chicago business activity bounced back into positive territory in October. Chicago PMI rebounded to its highest level since January, boosted by gains in new orders and production.