Walmart Inc. (NASDAQ:WMT) shares fell more than 9% Thursday after Chief Financial Officer John David Rainey warned that gasoline prices above $4 are changing consumer spending. The warning came as Walmart reported its weakest U.S. sales growth in more than six years. Customer transaction growth slowed to 1.5% from 3% in the previous quarter, while average spending per transaction increased 1.1%, down from 3.1% a year earlier. Walmart expects fuel-related costs to be about $2 billion above its original forecast, creating pressure both at the checkout and across its supply chain. Medicare-negotiated drug prices also weighed on sales, while July price cuts had not yet had time to lift demand. The pressure is unfolding as President Donald Trump escalates confrontation with Iran, Brent crude approaches $94 a barrel, and Polymarket traders put the chance of Strait of Hormuz traffic returning to normal by Oct. 31 at about 15%, with the odds of a U.S.-Iran nuclear deal by year-end at 11%. Walmart beat earnings estimates and raised its annual sales forecast, but its third-quarter profit guidance missed expectations. The retailer plans to cut prices on 11,000 items and reinvest nearly $2.9 billion in tariff refunds to support demand, though those measures cannot control fuel prices.