Key Points UnitedHealth stock has tumbled 35% this year amid a series of headwinds. The company has addressed certain challenges in recent months, and efforts are starting to bear fruit. 10 stocks we like better than UnitedHealth Group › This year hasn't been the easiest for UnitedHealth Group (NYSE: UNH). The biggest U.S. health insurer has faced several challenges, from the unexpected departure of its chief executive officer back in May to higher-than-expected medical cost trends, and even a Just ...