UnitedHealth shares soar after Warren Buffett's new stake provides a vote of confidence
1. UNH shares down nearly 50% in 2025 before Buffett's filing. 2. Facing investigation into Medicare billing practices amid rising healthcare costs. 3. CEO Andrew Witty's resignation followed a bleak earnings outlook. 4. Berkshire's investment is seen as a confidence boost for UNH. 5. Analysts view Buffett's move as a potential bottom for MCO stocks.