Surging medical costs and regulatory changes hit UnitedHealth, but rivals such as Humana and CVS look better positioned.

Humana Inc. closed 37.79% short of its 52-week high of $406.46, which the company reached on July 18th.

Shares of Humana Inc. HUM shed 1.51% to $249.53 Friday, on what proved to be an all-around grim trading session for the stock ...