Gas Prices Stay High, Costco Stock Could Be a Better Buy Than Walmart

Gas prices staying high is shaping consumer behavior, and Costco could be better positioned than Walmart to weather the shock. As of June 10, renewed U.S. strikes in the Iran conflict pushed oil higher, which typically lifts gasoline prices. In 2026, Walmart (WMT) and Costco (COST) have outperformed the S&P Retail Select Industry Index, with Costco also beating the S&P 500. Costco has posted slightly stronger returns than Walmart year-to-date, underscoring its gas-heavy business model. Walmart faces a customer mix that is increasingly budget-conscious as gas costs rise; during May 21 earnings calls, Walmart CFO John David Rainey said higher-income shoppers still spend with confidence, while lower-income customers cut back. He noted fuel-center customers are buying an average of under 10 gallons per visit—the lowest since 2022. Costco, by contrast, reports that gasoline is a meaningful revenue driver—roughly 10% of net sales—and recent quarters have shown record volumes. During the latest quarterly call on May 28, CEO Ron Vachris described 'record-breaking volumes,' with the last five weeks of the quarter among Costco's top five volume weeks. If gas prices remain elevated, Costco may maintain momentum even as discretionary spending tightens for others.