Shares of UnitedHealth Group are surging before the market open Friday as Warren Buffett’s Berkshire Hathaway disclosed that it recently purchased shares of the beleaguered insurer.

The Oracle of Omaha just took a $1.6 billion stake in the battered healthcare giant, sending shares soaring 9% after hours.

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.

Berkshire Hathaway revealed four new investments Thursday in steelmaker Nucor, insurer UnitedHealth and two of the nation’s biggest homebuilders — Lennar and DR Horton — but only one of the investments was big enough to ensure that legendary investor Warren Buffett may have handled them.

Warren Buffett's modus operandi is to wait for price dislocations to present themselves. In a historically pricey stock market, locating value has been virtually impossible. Yet, with UnitedHealth Group stock losing more than half its value since the midpoint of April, a rare price dislocation has emerged.

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.

UnitedHealth Group jumped nearly 4% on Wednesday, marking its fourth straight day of gains, and kept climbing after hours after the board approved a $2.21 per share quarterly dividend. The payment, set for Sept.

Warren Buffett's mystery stock purchase has sparked speculation and a frenzy. The only certain clue is that it's not a bank, insurer, or consumer products company.