Warren Buffett has lost over $265 million on historic UnitedHealth stock bet

UnitedHealth (NYSE: UNH) stock has plunged all the way back below the level at which Warren Buffett’s Berkshire Hathaway (NYSE: BRK.B), established its 2025 position. 

Notably, Berkshire acquired 5,039,564 shares of UnitedHealth during the second quarter of 2025, a new stake valued at $1.57 billion when the position was disclosed in mid-August. 

At the end of June 2025, when the quarter closed, UnitedHealth shares finished at $311.  By press time, the stock traded at $259, a drop of about 17%.

To this end, the decline has produced an unrealized loss of $267 million on the position from the June 30 closing value.

Indeed, Berkshire bought the shares sometime between April and June 2025. Exact transaction prices are not disclosed in regulatory filings, but the purchases occurred while UnitedHealth was already under severe pressure and trading well below its 2024 highs above $600. 

The investment marked Berkshire’s first meaningful ownership of the health insurer since it sold its earlier stake in 2010 after building an initial position late in 2006.

UNH stock troubles 

Notably, UnitedHealth’s troubles mounted throughout 2025 and created the opening for Buffett’s contrarian bet. 

The company’s medical care ratio surged from the mid-80% range to nearly 89% as claims costs accelerated far beyond expectations, driven by higher utilization of deferred post-pandemic care and elevated expenses in its Medicare Advantage business. 

UnitedHealth repeatedly slashed its 2025 earnings guidance, suspended the forecast entirely in May, and ultimately delivered results far below Wall Street projections. 

In the same period, the chief executive, Andrew Witty, stepped down for personal reasons and was replaced by former chief Stephen Hemsley. 

Adding to the pressure, the Justice Department opened a criminal investigation into possible Medicare fraud and billing practices in the company’s Medicare Advantage operations, following an earlier civil probe.

Overall, the combination of soaring medical costs, regulatory scrutiny, and repeated earnings disappointments erased more than a third of UnitedHealth’s market value during 2025 and left the stock vulnerable even after Berkshire’s purchase.