Warren Buffett's Berkshire Hathaway reveals new stake in beleaguered insurer UnitedHealth
1. Berkshire Hathaway acquired over 5 million shares in UnitedHealth, worth $1.6 billion. 2. UnitedHealth's stock rose 6% post-disclosure, amid struggles with operational challenges. 3. Berkshire also invested in Nucor, Lamar Advertising, Allegion, and homebuilders Lennar and DR Horton. 4. The position's confidentiality helped Berkshire limit volatility during acquisition. 5. UnitedHealth faces scrutiny from the DOJ over its Medicare billing practices.