On Saturday,Berkshire Hathaway (NYSE:BRK) (NYSE:BRK) registered a decline in third-quarter operating earnings, driven by weakness in the insurance underwriting segment. The Omaha-based company’s quarterly operating earnings of $10.09 billion slumped over 6% from $10.761 billion in the year-ago quarter. Approximately 70% of the aggregate fair value was concentrated in five companies, as of September-end 2024: American Express Company (NYSE:AXP) – $41.1 billionApple Inc. (NASDAQ:AAPL) – $69.9 billionBank of America Corporation (NYSE:BAC) – $31.7 billionCoca-Cola Company (NYSE:KO) – $28.7 billion…