1 Warren Buffett Stock to Buy Hand Over Fist in September

September is here, and it looks like the Federal Reserve's Federal Open Market Committee just might lower its benchmark interest rate again when it meets next week. Many stocks, especially those of companies that are particularly sensitive to interest rates, are already climbing in anticipation. As a bank and credit card network, American Express (AXP -0.28%) is very sensitive to interest rates. It was a standout stock last year, gaining 58%, and its gains so far this year are roughly in line with the S&P 500. If the federal funds rate gets the expected cut, Amex could benefit in a big way, and its stock could start to outperform again. Standing out in finance American Express is known for its credit and charge cards, but the company has become a lot more than that. It has a large banking segment that works together with its card network to create a closed-loop model, but each segment adds its own unique value to the whole. American Express targets an upscale clientele that prizes its card rewards programs, which offer travel perks and points, as well as discounts at premium shopping locations and restaurants. The company charges annual fees to cardholders for these privileges, and the fee income is a major part of its model. As a bank, American Express targets small businesses and offers a more boutique experience than many larger institutions. Image source: Getty Images. The bank also provides the credit to people using its cards, so it doesn't need to work with partner institutions. This also makes American Express a business that can perform well in different economic environments. When interest rates are higher, it makes more net interest income on its deposits. When the economy is doing well and customers are spending, it thrives. However, it usually demonstrates resilience when the economy is under pressure since its core customers have more money to spend, and since it collects its annual fees regardless of the macro conditions. That important recurring revenue stream keeps its profits coming in smoothly. Gaining momentum This all played out perfectly in 2025's second quarter. American Express's revenue increased 9% year over year (currency neutral) despite continued macroeconomic pressure, and adjusted earnings per share were up 17%. Card fees increased by 20% and accounted for almost 14% of the total. There was record cardmember spending in the quarter and high demand for premium products. The company frequently "refreshes" its card offerings and perks to stay relevant and attract new members, and it said it's going to launch a "major upgrade" to its U.S. business and personal platinum cards in the fall. If that coincides with greater access to money due to lower interest rates, it could be a recipe for robust growth. It's also focusing more on appealing to younger people, and that's paying off. While there was 7% increase year over year in cardmember spending in the second quarter, there was a 39% in Gen Z spending, and a 10% increase in millennial spending. Gen X still accounted for the most total spending of any age category at 36%, but the higher growth in younger categories bodes well for the bank's future. A longtime Buffett favorite Warren Buffett has praised American Express' global brand and the fact that it doesn't have to spend a lot of money to make a lot of money. He also loves to invest in companies that pay dividends and give back to shareholders through stock repurchase programs. American Express' dividend yields 0.9% at the current price. That's not a high yield, but its payouts are reliable, management has a long track record of maintaining or hiking them, and it repurchased $1.4 billion in stock in the second quarter. American Express is the paradigm of the Buffett stock, and he frequently references it as an example of a great business. If the Fed cuts interest rates as expected this month, American Express stock should jump. More importantly, higher economic activity should boost its business.