UnitedHealth Surges to 4th in Trading Volume on $1.57B Buffett Stake

On August 18, 2025, UnitedHealth (UNH) rose 1.47%, with a trading volume of $12.35 billion, ranking fourth in the market. This marked a 40.49% decline in volume compared to the previous day.

The stock’s pre-market surge was driven by Berkshire Hathaway’s disclosure of a $1.57 billion stake in UnitedHealth, including 5 million shares. This move, Warren Buffett’s largest equity holding in the healthcare sector, reinforced investor confidence in the company’s long-term prospects. Buffett’s history of investing in UnitedHealth since 2006 underscores his belief in the firm’s strategic position and resilience amid challenges such as rising medical costs and regulatory scrutiny.

Berkshire’s investment amplified market sentiment, positioning UnitedHealth as a key player in healthcare. Analysts noted that the stake could attract other institutional investors aligned with Berkshire’s strategy. However, the company still faces ongoing investigations, including a Justice Department probe into Medicare billing practices, which may temper sustained gains without operational improvements.

The strategy of buying the top 500 stocks by daily trading volume and holding them for one day from 2022 to 2025 yielded a 1-day return of 0.98% and a total return of 31.52% over 365 days. This highlights short-term momentum capture but also reflects market volatility and timing risks inherent in such strategies.