UnitedHealth Group Inc. (NYSE:UNH) extended its rebound Monday, climbing another 3% in premarket trading after soaring 12% on Friday. The surge followed revelations that Warren Buffett’s Berkshire Hathaway Inc.

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

UnitedHealth Group shares popped Friday after Berkshire Hathaway announced it purchased 5 million shares of the insurance giant.

Warren Buffett’s Berkshire Hathaway revealed a position in embattled healthcare giant UnitedHealth Group while showing smaller stakes in longtime holdings Apple and Bank of America, according to a regulatory filing Thursday.

Warren Buffett's Berkshire Hathaway has placed a major bet on a recovery at UnitedHealth Group, disclosing a new $1.6 billion stake in the insurance giant.

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.

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Warren Buffett has requested confidentiality in a new Berkshire Hathaway position. Will investors find out the stock Thursday?

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.