The investment comes as UnitedHealth faces soaring medical costs, federal investigations, the fallout of the killing of a top executive and a cyberattack last year.

Berkshire Hathaway recently filed its second-quarter 13F form, revealing its stock holdings at the end of June.

Warren Buffett's top 10 stock holdings in the Berkshire Hathaway portfolio shows a preference to several sectors.

Berkshire Hathaway’s portfolio added six new stocks, including the three new secret stocks. Warren Buffett was a net seller of stocks for the eleventh straight quarter.

The Oracle of Omaha sent two-thirds of his company's largest investment holding packing in favor of a 7.7% stake in a steadily growing, consumer-facing business.

Warren Buffett’s Berkshire Hathaway (BRK.B) sold shares in Apple (AAPL) last quarter, [while adding UnitedHealth](https:

Berkshire Hathaway has now gone six full weeks without closing above its 200-day moving average, the longest stretch the stock has been underwater in nearly three years. This kind of technical weakness is rare for the company,