UnitedHealth shares jumped 12 per cent on Friday after Warren Buffett’s Berkshire Hathaway snapped up a stake in the troubled US healthcare group.

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. Berkshire Hathaway bought around 5 million shares of UnitedHealth last quarter,

Warren Buffett's Berkshire Hathaway increased its holdings in UnitedHealth Group stock, and also added positions in D.R. Horton, Lamar Advertising, and Nucor.