Group 1: Investment Details - Berkshire Hathaway has made a significant investment in UnitedHealth Group, acquiring 5,039,564 shares at an average price of $311.97 per share, totaling approximately $1.57 billion [1] - The investment in UnitedHealth is one of Berkshire's most notable new entries in Q2 2025 [1] Group 2: Market Reaction - UnitedHealth's stock closed at $271.49, down 0.12%, but increased by 12.52% in pre-market trading to $305.48, indicating renewed optimism in the company's growth prospects [2] Group 3: Portfolio Reshuffle - The investment in UnitedHealth is part of a broader portfolio reshuffle by Berkshire, which also included new stakes in D.R. Horton, Lennar, and Nucor, while reducing positions in Apple and Bank of America [3] - Other prominent investors, including Michael Burry and David Tepper, also purchased shares in UnitedHealth during Q2, reflecting a wider interest in the company [3]