The advance came after Buffett's conglomerate Berkshire Hathaway revealed a stake of five million shares, worth about $1.6 billion.

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

UnitedHealth shares jumped 10 per cent in pre-market trading on Friday after Warren Buffett’s Berkshire Hathaway snapped up a stake in the troubled US healthcare group. The new investment, worth $1.6bn at the end of June, was disclosed in a filing late on Thursday detailing changes to Berkshire’s $268bn stock portfolio during the second quarter.

The blue-chip Dow briefly hit a record high on Friday, as UnitedHealth's shares jumped after Berkshire Hathaway raised its stake in the health insurer, while investors assessed mixed data to determine the Federal Reserve's next monetary policy move.

The blue-chip Dow briefly hit a record high today, as UnitedHealth’s shares jumped after Berkshire Hathaway raised its stake in the health insurer, while investors assessed mixed data to gauge the Federal Reserve’s monetary policy path this year.