The secret investments of Warren Buffett’s Berkshire Hathaway (NYSE:BRK) have been brought to light. What Happened: The undisclosed investments of Berkshire Hathaway have been made public. The company has reportedly invested in steelmaker Nucor (NYSE:NUE),

Beaten-down UNH is set to challenge its 50-day moving average after a major vote of confidence from the Oracle of Omaha.

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

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.

Buffett owned UnitedHealth shares before selling his stake in 2010, though his Berkshire Hathaway recently acquired shares.

Warren Buffett's Berkshire Hathaway has acquired 5 million shares in UnitedHealth Group , a regulatory filing showed on Thursday, sending the health insurer's stock up 7% in extended trading.

UNH stock soared after Warren Buffett’s Berkshire Hathaway revealed it bought shares of the healthcare company. Nonetheless, UnitedHealth faces a long list of unresolved issues.

Warren Buffett's Berkshire Hathaway built a $1.6 billion stake in UnitedHealth last quarter, marking one of its last wagers with the investor as CEO.