In the fourth quarter, Aquamarine Capital, led by value investor Guy Spier, cut its American Express position by approximately 69%. This sale followed a run-up in American Express’s trailing price-to-earnings multiple to 23.6 times, reflecting what Spier described as stretched valuations across consumer-finance names. Despite trimming the second-largest holding in his fund, Spier noted that American Express’s exposure to middle-income consumers and its premium franchise could offer attractive entry points should market volatility deepen. The sale reduced American Express’s weighting in Aquamarine’s portfolio to under 10%, down sharply from prior levels.

American Express faces heightened regulatory uncertainty after President Donald Trump called for a one-year cap of 10% on credit-card interest rates and disclosed private discussions with card issuers. JPMorgan Chase CEO Jamie Dimon warned such a cap would be “an economic disaster,” predicting a sharp reduction in credit availability for 80% of consumers. If enacted legislatively or via regulatory action, a 10% cap could force American Express to tighten underwriting standards, curtail revolving-balance growth and sacrifice up to $5 billion in annual net interest income, according to bank analysts. Investors will watch both congressional hearings and state-level pilot proposals, such as those suggested for Vermont and Massachusetts, for early signs of binding constraints on card APRs.