Annual market cap and P/E ratio of American Express (Amex) 2008-2024

Amex' valuation multiples nearly doubled in 2024, similar to when the P/E ratio of this particular stock grew substantially in 2009, 2017, and 2020. This is according to a historical timeline of Mastercard's market capitalization and price-to-earnings, or P/E, ratio. American Express works differently from other global card networks like Visa and Mastercard, in that Amex is also a credit card issuer. This means American Express financials are closely tied to credit card interest rates, and the fees on such cards. Visa and Mastercard, however, focus more strongly on revenue from transaction volume. This does mean that when the U.S. Fed announced its long-awaited plans to lower the central bank interest rate, the stock price of Amex fell - as investors could question the profitability of American Express in an environment with lower interest rates.