American Express: A Deep Dive Through Buffett's Lens

Warren Buffett's relationship with American Express (NYSE: AXP) is the longest-running story in Berkshire Hathaway's equity book, and one of the clearest illustrations of how his philosophy evolved from "cigar-butt" bargains into owning wonderful businesses forever. The first chapter opened in 1963, when a warehousing fraud known as the salad-oil scandal knocked Amex stock from $61 to $35. A young Buffett, then running the Buffett Partnership, visited New York restaurants and hotels to check one thing: were customers still charging on Amex cards? They were. Concluding that the brand and its network effect were intact, he put roughly 40% of the partnership's capital into the stock and more than doubled his money within three years.

The chapter that matters to ValueOS readers is the second one. In 1991, Berkshire Hathaway bought $300 million of Amex preferred stock; in 1994 it converted those securities and added to the position, eventually committing about $1.3 billion. Buffett has not sold a share since. Today American Express is Berkshire's second-largest equity holding after Apple, with Berkshire owning roughly one-fifth of the company. That stake grew not from new purchases but from Amex's own buybacks shrinking the float — a quiet compounding machine that few other positions can match.

The Moat: A Closed Loop Few Banks Can Replicate

Most payment networks are "open loop." With Visa or Mastercard, the network merely connects an issuing bank to an acquiring bank and takes a small toll. American Express is different. In the majority of its transactions, Amex is simultaneously the issuer and the network — a closed-loop system that captures the entire economics of a charge. That structure lets Amex know exactly who spends what, where, and how, which in turn supports premium service, targeted offers, and industry-leading fraud controls.

The result is pricing power. Merchants pay Amex a higher "discount rate" than they pay open-loop networks because Amex delivers affluent, high-spending cardholders that retailers want. Cardholders pay annual fees for Platinum and Gold products they could drop but choose to keep because of the status and perks. Buffett has put the point bluntly: "The single most important decision in evaluating a business is pricing power. If you've got the power to raise prices without losing business to a competitor, you've got a very good business. And if you have to have a prayer session before raising the price by a tenth of a cent, then you've got a terrible business. We've seen that with American Express." It is hard to imagine a cleaner statement of why the brand value of Amex matters more than its balance sheet.

Financially, the model shows up where it should. Amex has generated returns on equity in the low-to-mid 30s percent in recent years, with net margins above 25% and record full-year revenue of roughly $66 billion in 2024. Those are the figures Buffett means when he says a business must earn high returns on capital for a long time — the quantitative fingerprint of a durable economic moat.

Capital Allocation: Disciplined Return of Cash

American Express is a capital allocation case study in the right way. It generates more cash than it needs to fund loan growth, so management returns the surplus through dividends and, more importantly, buybacks. Because Berkshire did not sell, the shrinking share count mechanically raised Berkshire's ownership from roughly 10% to more than 20% — "free" incremental ownership that illustrates why Buffett favors companies that repurchase stock when it is cheap. The discipline matters: Amex has bought back shares consistently through cycles rather than chasing prestige acquisitions, exactly the behavior a long-term owner wants.

This mirrors the logic Buffett applies across his consumer and financial holdings. Let great businesses compound, and let management return what they cannot reinvest at high rates. It is the same patience he shows with Coca-Cola, another franchise he has never felt compelled to trim, and it is the opposite of empire-building for its own sake.

Valuation and Margin of Safety

A wide moat tells you about durability, not about price. American Express is a wonderful business, but its premium brand and premium multiples mean the margin of safety depends entirely on the entry price. Buffett's own cost basis sits far below today's quote, which is why his holding is untouchable even when the stock wobbles. For a new investor, the question is whether current intrinsic value supports the price after allowing for credit losses in a downturn and for competition from the open-loop networks and from fintech entrants.

ValueOS frames this honestly: the business quality is not in dispute, but the price you pay determines your return. The tools on this site let you model the cash the business truly throws off and discount it yourself rather than trusting a headline multiple. A wonderful business at the wrong price is still no bargain — a lesson Buffett learned early and one Amex tests continuously.

Risks to Watch

• Credit sensitivity. Amex lends to cardholders; a deep recession would raise write-offs and compress profits.
• Competition. Visa, Mastercard, and a wave of fintech players compete for both the premium spender and the merchant discount.
• Regulation. The 2010s antitrust "anti-steering" fight went to the Supreme Court, where Amex won in 2018, but merchants and politicians keep pressing on swipe fees.
• Premium-position fragility. The model depends on affluent consumers continuing to value status perks; a long consumption slump would bite.

What Value Investors Should Take Away

American Express rewards investors who stay inside their circle of competence: a payments business is understandable, its moat is visible in the numbers, and its management has behaved like owners. Buffett's half-century with the name — buying the panic in 1963, building the permanent position in the 1990s, and never selling — is a masterclass in separating a company's temporary troubles from its permanent advantages. The takeaway is not "buy Amex today at any price." It is to study the moat, demand a margin of safety, and then let time and disciplined capital return do the rest.