This Is How Much Costco Stock Has Gained Over the Past Year (It Might Surprise You)

Costco reported fiscal 2026 Q4 sales growth of 11.2%, comparable-sales growth of 9.4%, and EPS rising to $6.75 from $5.87; September sales then increased 13% year over year, with comps up 11.2%. Membership sign-up growth slowed in Q4, which management attributed to a strong year-ago comparison and no major Asia openings, while U.S. and Canada renewal rates were 92.3% and global renewal rates were 89.8%. The article says the stock remains expensive at 46 times earnings despite strong results, leaving potential downside.

Analysis

The key risk is not a near-term collapse in demand; it is the gap between Costco’s durable operating model and the duration of growth investors are paying for. A premium multiple makes even healthy sales vulnerable if membership growth or comparable-sales momentum merely normalizes: multiple compression could outweigh earnings growth over the next 1–3 months. The second-order test is customer quality. Digital acquisition may widen the younger-member funnel, but if those cohorts renew or spend less, headline sign-ups would overstate the value of the investment. Track renewal rates by channel/cohort, member income, traffic versus average ticket, and comps excluding fuel and FX; the article does not provide enough detail to establish cohort economics.

Over 6–18 months, store openings and customer acquisition can sustain the flywheel, while price investment protects value perception but may constrain merchandise margins. Competitors could face pressure to match value, though Costco’s membership economics make simple price matching less effective. The contrarian case is that decelerating sign-ups may be a comparison/opening-timing effect rather than weakening loyalty; strong renewal and sales trends argue against treating the business as impaired. There is no clear fundamental short absent evidence that member economics are deteriorating. The valuation remains the main vulnerability, not the operating thesis.

Key Decisions for Investors

• Avoid chasing strength after sales updates; treat COST as a quality holding, but require fresh evidence of durable earnings growth before adding at a premium valuation.
• Relative-value watch: consider a small short-COST/long-Walmart pair only if COST fails to hold gains after its next results while Walmart’s operating momentum remains intact. This expresses valuation-duration risk rather than a call on retail demand; cap risk because continued Costco comp strength could widen the premium.
• Near-term catalyst: next earnings and monthly sales updates. Reassess the cautious view if member-income growth and renewal rates remain firm alongside traffic-led comps; strengthen it if renewal rates or member income weaken for more than one reporting period, or guidance signals margin pressure.
• Do not equate slower sign-ups with churn without channel-level data. Seek digital-cohort renewal and spend metrics; absent those, treat sign-up deceleration as an alert, not a standalone short signal.