Buy American Express stock now, says the article

Warren Buffett is stepping down as CEO of Berkshire Hathaway after 65 years, and American Express is highlighted as a strong investment opportunity. The stock is trading 15% below its 52-week high. American Express, a key holding in Berkshire's portfolio, is favored for its brand and focus on affluent consumers. The company's closed-loop payment system and direct customer relationships are key advantages. Despite competition and economic uncertainties, American Express's performance metrics remain strong, making it a solid long-term investment, according to the article. The recent price drop presents a buying opportunity.