Walmart vs. Costco: Which Retail Giant Offers Better Upside for 2026?

Investment Showdown: Walmart vs. Costco for 2026

Recent quarterly results have highlighted divergent strategies between retail giants Walmart (NASDAQ:WMT) and Costco (NASDAQ:COST). As both companies navigate the same consumer environment, investors are weighing which model holds more upside potential heading into 2026.

Walmart’s Digital and Advertising Momentum

Walmart reported a robust fourth quarter, capping a year defined by digital acceleration. Global advertising revenue surged 37% to reach $6.4 billion annually. U.S. eCommerce growth hit 27%, while global eCommerce expanded 24%. Store-fulfilled expedited delivery volumes increased more than 50%.

The advertising segment remains the standout driver. Walmart Connect U.S. grew 41%, bolstered by the VIZIO acquisition which expanded connected TV advertising reach. Approximately 50% of eCommerce fulfillment center volume is now automated, compressing costs as scale increases. The company has gained share across all income tiers, with upper-income households leading the shift.

Costco’s Membership Flywheel

Costco followed in early March with results reinforcing its membership model. Comparable sales grew 7.4%, with global traffic up 3.1%. Fee income rose 13.6% to $1.35 billion, while paid memberships reached 82.1 million. The worldwide renewal rate held steady at 89.7%.

Executive membership penetration accounted for 75.8% of sales. Digital engagement improved significantly, with app visits jumping 63% and e-commerce average order value rising 15%. Personalization carousels drove over $470 million in e-commerce sales in Q2. The warehouse expansion plan targets approximately 28 net new locations in FY2026.

Valuation and Margin Structures

Valuation metrics suggest different risk-reward profiles. Costco trades at a forward P/E of 48x, with valuation pressure noted at 51x trailing earnings. Its gross margin sits structurally thin at 11.02%, limiting management levers when costs rise.

Walmart sits at 40x forward earnings. The company’s diversified growth engine combining retail media and eCommerce offers more earnings expansion potential than Costco’s membership-focused model. Walmart’s FY27 guidance projects adjusted EPS of $2.75 to $2.85.

Market Context

Both businesses are executing well in a competitive landscape. However, the structural differences in revenue streams define their investment cases. Walmart's scale and digital momentum provide multiple levers for earnings growth, whereas Costco relies heavily on membership loyalty metrics which remain extraordinary but command a premium valuation.

Investment Takeaway

Walmart’s advertising business provides a margin expansion path that Costco’s model structurally cannot match. While Costco’s renewal rate and Kirkland loyalty metrics are strong for long-term investors, the stock prices in significant future perfection at current multiples. Walmart's 46.33% one-year return reflects strong momentum, yet its forward multiple still sits below Costco's, offering a more accessible entry point with diversified growth drivers.