Berkshire Hathaway’s public equity portfolio sits at $359 billion, and nearly 14% of it is concentrated in a single financial stock that has more than doubled over the past five years. The conglomerate owns 22.5% of American Express, making the card network its second-largest holding behind Apple despite years of trimming the iPhone maker. Shares closed at a price-to-earnings multiple of 19.5, 17% below the December 2025 peak.
The moat is the brand and the network
American Express passes the quality test Warren Buffett and Greg Abel apply to capital allocation. The premium brand attracts affluent customers who value perks and rewards, which in turn produces industry-leading charge-off rates. The payments infrastructure creates a network effect that strengthens as merchant acceptance and cardholder counts grow, placing the business in the same structural tier as Visa and Mastercard.
Growth is steady, not spectacular
Management targets 10% annual revenue growth and mid-teens earnings-per-share compounding over the long term. Second-quarter network volume reached $456 billion, up 9% year over year. The cashless-economy tailwind continues to push more transactions onto the network, and the company is adding younger cardholders at scale, 65% of new global accounts in the latest quarter came from millennial and Gen Z cohorts, a group that has shown willingness to pay higher fees.
Platinum refresh lifts fee revenue
The Platinum card was relaunched last September with a $200 annual fee increase to $895. On the Q2 2026 earnings call, CEO Steve Squeri said the Platinum portfolio is now the fastest-growing segment in the U.S. consumer business. That pricing power supports the argument that the premium franchise can sustain above-average returns even in a mature industry.
Valuation offers a margin of safety
The stock’s 17% pullback from its December high has brought the multiple to 19.5 times earnings, a level that looks reasonable for a business with durable competitive advantages and a shareholder base that includes one of the most disciplined allocators in capital markets. Berkshire’s 22.5% stake is not new, but the recent price action has made the position cheaper without changing the underlying economics.