Health-insurance giant said it was making a number of governance changes, including the appointment of a new lead independent director and the formation of a public responsibility committee.

UnitedHealth Group (UNH) stock is still down 40% YTD but has surged more than +20% this month following reports that Warren Buffett, and other billionaire hedge fund managers have taken a stake in the company.

The company also unveiled a new Public Responsibility Committee and appointed former Vanguard chief executive F. William McNabb as lead independent director.

This investment signifies Buffett's re-entry into UNH after liquidating his entire position back in 2010, indicating that he perceives significant value at

UnitedHealth Group Inc. and Elevance Health Inc. told Colorado regulators they will exit some individual health plans in the state, the latest sign of instability in the Affordable Care Act marketplaces.

Following an investment by Warren Buffett's Berkshire Hathaway, many eyes are on the healthcare insurer these days.

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.

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.

UnitedHealth was a star stock late last week, when it was revealed that Warren Buffett's Berkshire Hathaway had taken a $1.6 billion stake in the company's equity. On Monday, lingering positive sentiment on UnitedHealth was boosted by that price target bump.

Year to date, the stock has fallen by nearly 45%, which is by no means normal for the healthcare stock. In fact, this is the worst it has performed since the Great Recession, when it tumbled by more than 54% in 2008.

UnitedHealth Group completed its $3.3 billion purchase of Baton Rouge-based Amedisys Thursday morning, more than two years after plans to join the nation's two largest home health and hospice care companies were first announced.