Core Viewpoint - Despite nearing retirement, Buffett's ability to identify valuable investments remains strong, as evidenced by significant stock purchases in the second quarter by Berkshire Hathaway, particularly in UnitedHealth Group, which saw a notable pre-market surge of over 12% [1][4]. Group 1: UnitedHealth Group - UnitedHealth Group's stock price has experienced a dramatic decline of over 50% in the past 12 months, resulting in a market value loss of nearly $270 billion [4]. - The company is currently under investigation by the U.S. Department of Justice regarding its Medicare Advantage billing practices, with allegations of improper diagnosis coding to inflate patient risk scores for higher reimbursements [6]. - Following a series of scandals and disappointing earnings reports, UnitedHealth's management underwent significant changes, including the appointment of a new CEO after a 27% stock price drop in May [6][4]. - Buffett's Berkshire Hathaway acquired over 5 million shares of UnitedHealth in the second quarter, with a market value of approximately $1.57 billion at the end of the quarter [7]. Group 2: Other Stocks Purchased by Berkshire Hathaway - In addition to UnitedHealth, Berkshire Hathaway also made significant purchases in six other stocks during the second quarter, including Nucor Steel (over 6.6 million shares), Lennar (over 7 million shares), and D.R. Horton (148,500 shares) [10]. - The total market value of these new positions at the end of the second quarter was approximately $3.65 billion [10]. - Other stocks that saw price increases in the pre-market include Nucor Steel (over 7%), Lennar (over 6%), and D.R. Horton (over 5%) [10].