Costco's Q4 Sales Rise 11.3% as Digital Momentum Remains Strong

Costco's fiscal 2026 fourth-quarter net sales rose 11.3% year over year to $93.9 billion, while companywide comparable sales increased 9.4%. Digitally enabled comparable sales grew 19.5%, materially outpacing core comparable-sales growth, and increased 20.9% for the full 52-week year. Despite strong operating momentum, Costco shares have fallen 6% over three months and trade at a 40.71x forward P/E versus the industry's 29.13x; consensus forecasts fiscal-year sales and EPS growth of 9.6% and 13.5%, respectively.

Analysis

The key investable issue is whether Costco’s digital mix is becoming incrementally accretive rather than merely a convenience layer. If digitally enabled transactions are increasingly warehouse-pickup and higher-frequency replenishment orders, COST can gain wallet share without bearing the full last-mile economics that pressure AMZN and TGT. That supports renewal rates and membership-fee pricing power over the next 6-18 months, but only if digital growth does not shift mix materially toward lower-margin bulky delivery categories.

COST’s valuation leaves little tolerance for a normalizing U.S. comp trajectory. The near-term sales release should protect sentiment, but a 1-3 month rerating requires evidence that gross margin, membership income, and traffic—not inflation, gasoline, or ticket—are carrying earnings. At roughly a premium multiple to retail peers, even a modest earnings-guide miss or evidence of digital fulfillment-cost deleverage could produce disproportionate multiple compression; the sales print alone is not sufficient to underwrite further upside.

BJ is the more asymmetric read-through: its digital adoption can narrow Costco’s convenience advantage in markets where BJ has club density, while its lower valuation provides more room for operating leverage if membership and food inflation remain constructive. TGT’s faster fulfillment proposition is strategically relevant but economically ambiguous, since same-day delivery growth can dilute margins absent basket-size improvement. The contrarian view is that the market may over-credit digital growth across the group: retail digital penetration is valuable only where membership economics or pickup density absorbs fulfillment costs.

For COST, watch the next earnings release for merchandise gross-margin expansion excluding fuel, paid-member growth, renewal rates, and SG&A as a percentage of sales. A deterioration in any two of these measures, or forward EPS growth falling below low-double digits, would falsify the premium-multiple thesis; conversely, sustained traffic-led comps plus margin expansion would justify retaining the quality premium.

Key Decisions for Investors

• Maintain a neutral-to-modest long COST only on pullbacks; add if the stock retraces another 5-8% without a downgrade to membership, traffic, or gross-margin outlook. Underwrite a 6-12 month quality-compounder return rather than chase a sales-release reaction; reduce if forward EPS revisions turn negative.
• Initiate a 3-6 month pair trade long BJ / short COST in equal dollar amounts if the valuation gap remains wide and BJ demonstrates stable membership metrics plus positive merchandise-margin leverage. This expresses digital/convenience convergence while hedging broad consumer-staples retail beta; exit if BJ’s comparable sales decelerate materially or shrink rises.
• Avoid using TGT’s digital growth as a standalone bullish catalyst until fulfillment economics are disclosed through gross-margin and SG&A improvement. Use TGT only as a watch item: upgrade the thesis if digital growth coincides with margin expansion, not merely sales growth.
• Set an earnings alert for COST: traffic-led comparable-sales deceleration below mid-single digits, membership-fee income growth below expectations, or SG&A deleverage would warrant cutting long exposure because the likely downside is multiple-driven rather than a gradual earnings reset.