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

Rising oil prices, driven by new strikes in the Iran conflict, push gasoline costs higher and influence discretionary spending. Costco has outperformed Walmart in 2026, with COST up 0.67% and Walmart up 0.44% as both march ahead of the S&P Retail Select Index and the S&P 500. Walmart’s higher-income customers remain confident, while lower-income shoppers are more budget-conscious, and gasoline customers at Walmart are buying less than 10 gallons per visit—the lowest since 2022. Costco, meanwhile, reports gasoline sales comprising about 10% of net sales, with “record-breaking volumes” in its latest quarter; management says higher gas volumes strengthen member loyalty and encourage deeper shopping.