1. Todd Combs leaves Geico to join JPMorgan, indicating leadership changes at Berkshire. 2. Greg Abel faces scrutiny as Buffett's successor amid rising executive turnover. 3. Berkshire's stock valuation premium may narrow post-Buffett era, impacting investor sentiment. 4. Market response shows Berkshire stock dropped 7.9% since Buffett's retirement announcement. 5. Challenges include potential profit declines at key subsidiaries like Geico and Reinsurance.