UnitedHealth Dives To 4-Year Low On Cost Warning, CEO Exit

UnitedHealth Group announced the immediate resignation of CEO Andrew Witty for personal reasons on Tuesday and withdrew its already-slashed full-year earnings outlook, citing a continued acceleration in medical cost trends. UNH stock, which had already been the worst Dow Jones performer this year, dived to its lowest level in more than four years. UnitedHealth is holding an investor call at 8 a.m. ET to discuss company developments.