Berkshire Hathaway is gearing up for the biggest leadership shake-up in decades, and one strategist thinks it presents the perfect time to buy the stock. Barbara Goodstein, a managing partner at R360, an invitation-only investment and networking group for ultra-high-net-worth individuals, told CNBC on Monday that longtime Berkshire CEO Warren Buffett's impending departure offered a "lot of opportunity" for investors.Buffett, 95, is set to step down as the CEO of Berkshire at the end of 2025 after nearly 60 ...