Shares of UnitedHealth Group ( UNH 3.45%) are plummeting this week. The company's stock is down 27.4% as of 12:29 p.m. ET. The collapse comes as the S&P 500 ( ^GSPC 0.27%) gained 4.7% and the ...

UNH has lost more than $200 billion in market value in the last six months. The company’s old CEO sees a fix. Investors ...