Costco can be an excellent operating business without being an automatically attractive stock at every price. To decide whether COST belongs in your portfolio, examine three separate questions: whether the membership-warehouse model is producing durable results, whether the market price is reasonable for those results, and whether owning one large retailer suits your existing holdings, time horizon, and ability to absorb losses.
The latest complete annual figures are for Costco’s 52-week fiscal year ended August 30, 2026. They show strong growth, but they do not answer the valuation or portfolio-fit questions. Use the framework below to make those judgments without turning a company-quality assessment into a blanket buy, sell, or hold recommendation.
As an Amazon Associate I earn from qualifying purchases.
Start by separating the business from the stock
A stock represents a claim on a business, but the return you earn depends on both the business’s future performance and the price you pay for that claim. A company can increase sales and profits while its shares fall if investors had already priced in even better results. Conversely, a temporarily unpopular stock can recover if results stabilize and expectations become achievable.
For Costco, assess the operating business first, then test the share price against realistic expectations. Finally, consider how a single position would change your portfolio. Someone seeking a long-term individual-company holding may reach a different conclusion from someone who already owns broad funds with substantial large-cap retail exposure or who needs the money within a few years.
#1 Best Overall
What Costco does and how its model works
Membership warehouses and e-commerce
Costco Wholesale Corporation operates membership warehouses and e-commerce sites. It emphasizes a limited selection of branded and private-label products, low prices, high sales volumes, and rapid inventory turnover. The limited assortment concentrates purchasing power and simplifies operations, while membership fees support the economics of offering low merchandise prices.
Common stock trades on the Nasdaq Global Select Market under the ticker COST. At August 30, 2026, the company reported 939 warehouses worldwide. The geographic footprint matters because results reflect local consumer demand, foreign exchange, fuel prices, labor costs, and the maturity of each market rather than a single national retail environment.
Why membership behavior matters
Members pay for access before buying merchandise. That fee stream is a recurring indicator of customer retention and gives management another lever besides product markups. Renewal rates, membership additions, upgrades, and spending per member therefore deserve as much attention as headline sales.
The Tool Desk
Outbyte Driver Updater FREEFix the driver behind crashes, sound loss and screen glitchesFind Drivers →Outbyte PC Repair FREEClear out junk files and repair common Windows errorsFree Scan →The model also creates a high expectation for value. If customers believe prices, selection, convenience, or digital service have deteriorated, they can let memberships lapse and shift purchases elsewhere. A strong renewal rate is encouraging, but it is not a guarantee that future fee growth or merchandise margins will persist.
What the FY2026 numbers actually show
The following figures come from Costco Wholesale Corporation’s FY2026 Form 10-K, filed October 7, 2026. They are historical results for the 52-week year ended August 30, 2026, not forecasts. Dollar amounts are nominal and shown in billions unless noted.
Rank #2
- Ideal for Gifting
- Ideal for a bookworm
- Compact for travelling
| Measure | FY2026 result | Year-over-year change or context |
|---|---|---|
| Net sales | $297.247 billion | Up 10% |
| Net income | $9.226 billion | Up 14% |
| Diluted earnings per share | $20.76 | Reported FY2026 amount |
| Membership fee revenue | $5.907 billion | Up 11% |
| Renewal rate, United States and Canada | 92.3% | Measured at fiscal year-end |
| Worldwide renewal rate | 89.8% | Measured at fiscal year-end |
| Total comparable-sales growth | 8% | Company-reported FY2026 growth |
| Gross margin percentage | 11.09% | Down 3 basis points |
| Gross margin excluding gasoline-price inflation impact on net sales | 11.22% | Up 10 basis points |
Sales and earnings growth indicate that demand and operating leverage were solid during the year. Membership fee growth and renewal rates provide a second lens: they show whether the customer relationship supporting the model remains healthy. Comparable sales help distinguish growth at existing locations from growth created merely by opening warehouses.
Margin figures require context. Costco said the reported gross-margin percentage declined slightly, while the measure excluding the effect of gasoline-price inflation increased. Fuel prices and sales mix can move reported sales and margins even when underlying merchandising decisions have not changed. Read several periods together instead of treating one quarter’s margin movement as a complete thesis.
What’s actually slowing this PC down?
Pick the symptom - the matching free tool is one click away.
How to judge the durability of Costco’s growth
Comparable sales versus new locations
Comparable sales measure activity at warehouses and channels open long enough to be included in the company’s comparison. Sustained comparable growth suggests existing locations are attracting more visits, higher basket values, or both. New warehouses can raise total sales while producing little evidence that the established base is strengthening, so track the two sources separately in future filings.
Membership fees and renewal rates
Membership fee revenue is generally less dependent on the markup on any one product. Examine whether fee growth comes from more members, a larger share of higher-tier memberships, price changes, or some combination. Renewal rates should be read by geography and over time; a worldwide rate can move differently from the more mature United States and Canadian base.
Profit growth and reinvestment
Net income and diluted earnings per share show what reached shareholders after operating costs, interest, taxes, and other items. Compare profit growth with sales growth and watch whether expansion requires rising capital spending, working capital, or debt. A retailer that grows quickly but earns little incremental return on new warehouses may not create value at the same rate as its revenue.
Price discipline and gross margin
Costco’s low-price promise can require it to hold prices steady or reduce them when supplier costs rise or competitors become more aggressive. That choice can pressure gross margin while protecting customer loyalty and volume. A falling margin is not automatically a failure, but investors should ask whether the sacrifice is producing stronger membership economics and durable sales.
Free tools Windows power users keep installed
One-click scans. No signup required.
Valuation: the missing half of the decision
Operating results cannot establish that COST is cheap, fairly valued, or expensive. Before making a decision, record a dated share price and calculate the valuation measure you intend to use. Do not quote a multiple without identifying the earnings period and the price date.
Core measures to calculate
- Price-to-earnings: Divide the share price by trailing diluted earnings per share, or by a clearly identified forward estimate. Trailing and forward ratios answer different questions; never mix them.
- Free-cash-flow yield: Compare the latest annual or normalized free cash flow with the company’s market value. Explain how you define free cash flow and whether a year included unusual working-capital effects.
- Enterprise value to operating earnings: Use enterprise value when comparing companies with different debt and cash balances, and specify the earnings measure used.
- Growth-adjusted expectations: Test what sales, margins, membership fees, and earnings would need to do to justify the current price. This is a scenario exercise, not a promise of future returns.
A repeatable valuation process
- Write down the closing share price and the date and time zone of the quote.
- Choose trailing twelve-month earnings, the latest fiscal-year earnings, or a forward estimate; label the choice next to every multiple.
- Build at least a conservative, central, and optimistic earnings path using assumptions you can explain.
- Apply a valuation range to each path rather than pretending one precise multiple is correct.
- Compare the implied return with the risk of disappointing results and with the return you require for an individual stock.
- Repeat the exercise after the next annual or quarterly filing, because a price that looked reasonable can become demanding after a rally.
Costco’s own FY2026 filing says, “We believe that the price of our stock currently reflects high market expectations for our future operating results.” That is the company’s statement, not independent proof of fair value. Treat it as a reminder to test expectations explicitly. The filing also warns that missing expectations for comparable sales, membership fee revenue, gross margin, earnings, earnings per share, warehouse openings, or dividend and repurchase policies could cause the share price to decline.
Portfolio fit: what owning COST would change
Concentration by company and sector
List every fund and stock you own, then look through fund holdings where available. A new COST position may increase exposure to U.S. equities, large-cap companies, consumer staples, retail, logistics, and discretionary household spending even if Costco is the only individual retailer you buy. The relevant question is your total economic exposure, not the number of tickers.
Time horizon and liquidity
An individual stock can decline for reasons unrelated to a permanent deterioration in the business, including a change in valuation multiples or a missed quarterly expectation. Money needed for near-term rent, tuition, taxes, a house purchase, or emergency reserves generally should not depend on a single company’s share price. A longer horizon can provide more time for operating results to matter, but it does not eliminate the possibility of a lasting loss.
Rank #4
Capacity for volatility
Ask how you would react if COST fell sharply while membership and sales indicators remained healthy. If you would sell solely because of a headline, the position may be too large or unsuitable. Write a maximum position size and the facts that would change your thesis before buying; this reduces the chance of making an emotional decision after a decline.
Single stock or diversified exposure
If your goal is broad market participation, an existing diversified fund may achieve that objective with less company-specific risk. If your goal is to own a business you have studied and to accept tracking error against the market, a measured COST position may be more appropriate. Do not choose between these approaches based only on a recent performance chart.
Risks that can break the Costco thesis
Broad and intense competition
Costco says it competes with warehouse clubs, supermarkets, supercenters, online retailers, gas stations, pharmacies, discount stores, department stores, specialty stores, and other sellers. Competition can involve price, product selection, availability, service, location, convenience, store hours, and digital experience. A competitor does not need to copy the entire warehouse model to pressure a particular category or customer trip.
Margin pressure from value decisions
Holding prices down when costs rise can protect the membership proposition but reduce merchandise margin. Passing costs through to shoppers may protect margin temporarily while weakening traffic or renewals. Evaluate the trade-off through several years of comparable sales, member behavior, and profitability rather than assuming the company can raise prices without consequences.
Fuel prices and sales mix
Gasoline prices affect reported sales, and fuel is only one component of the merchandise mix. A higher fuel price can lift nominal revenue without representing equivalent unit growth; a lower price can do the reverse. When comparing periods, isolate the effect where the filing provides that information.
Best Value
- It can be a gift option
- Comes with secure packaging
- Helpful in various ways
High expectations and execution
Investors may already expect rapid comparable sales, continuing membership growth, successful warehouse openings, stable margins, and shareholder returns. A business can meet its own prior-year result yet disappoint the market if the result is below the expectation embedded in the share price. Expansion also brings site-selection, labor, supply-chain, technology, and international-execution risks.
Retail-cycle and macroeconomic risks
Household budgets, employment, inflation, interest rates, currency movements, and supplier conditions can change purchasing patterns and costs. Membership warehouses may benefit when shoppers seek value, but they remain exposed to weaker discretionary demand and lower volumes in some categories.
Independent reader supportYour contribution helps us test, update, and keep practical guides available for everyone.A practical decision workflow
- Define the role. Write whether COST is intended as a long-term compounder, a smaller satellite position, or a short-term trade. The evidence and risk controls differ.
- Read the latest filing. Confirm the fiscal period, comparable-sales definition, membership statistics, margin bridge, capital spending, debt, cash flow, and share-count changes.
- Track the operating dashboard. Maintain a simple log of comparable sales, membership fee revenue, renewal rates, net income, diluted EPS, gross margin, warehouse openings, and digital trends.
- Update the price. Use a dated market quote and calculate clearly labeled valuation ratios. Replace stale figures after material earnings releases.
- Stress-test assumptions. Model slower comparable sales, weaker renewal rates, lower margins, delayed openings, or higher investment spending. Identify which assumption has the largest effect on value.
- Map portfolio overlap. Estimate the exposure you already have through funds and other companies, including broad U.S. and large-cap allocations.
- Set a risk rule. Decide in advance what evidence would invalidate the thesis and how much capital you can lose without compromising essential goals.
- Choose an action. Buy, wait, add gradually, maintain an existing position, or use diversified exposure only after the business, valuation, and portfolio tests agree. The framework does not require an immediate purchase.
How to interpret future updates
If comparable sales accelerate
Check whether the improvement is broad across categories and regions, whether membership fees and renewals confirm stronger engagement, and whether the gain required unusually low prices that reduced margin. Strong traffic with deteriorating economics is a different outcome from strong traffic with stable profitability.
Recommended Free Tools
If membership growth slows
Separate a temporary timing effect from weaker acquisition, lower renewal, fewer upgrades, or reduced spending per member. A slower fee line may be manageable if merchandise productivity and cash generation improve, but it deserves a lower growth assumption until evidence changes.
If margins expand
Determine whether the benefit came from product mix, purchasing, fuel comparisons, lower costs, or a one-time factor. Durable process improvements support a different valuation from a favorable commodity or accounting comparison.
If the share price rises faster than earnings
Recalculate the multiple using the new dated price. A rising price can be justified by better long-term expectations, but it also reduces the margin of safety if operating results do not catch up. Avoid using past returns as evidence that the next purchase will earn the same result.
Common mistakes to avoid
- Confusing popularity with value: A loved retailer can still be overpriced.
- Using one renewal rate as a guarantee: Renewal is a lagging, geographic, and time-specific measure.
- Ignoring gasoline effects: Fuel-price changes can distort sales and margin comparisons.
- Counting new warehouses as proof of productivity: Expansion should be evaluated alongside comparable performance and returns on invested capital.
- Quoting an undated P/E ratio: Always attach the price date and earnings period.
- Overlooking portfolio duplication: A fund may already own a meaningful position in large U.S. retailers.
- Relying on the company’s expectations statement as valuation analysis: Management’s warning identifies risk; it does not establish fair value.
- Making a personalized allocation from company results alone: Position size depends on goals, liquidity, taxes, other assets, and risk capacity.
Questions to answer before you buy or add
| Question | Evidence to collect | Decision implication |
|---|---|---|
| Is the operating trend durable? | Several periods of comparable sales, membership fees, renewals, margins, and earnings | Determines whether your growth assumptions are supported |
| What is already priced in? | Dated share price, trailing or forward earnings, cash flow, and an explicit valuation range | Shows how much disappointment the price can absorb |
| How concentrated would I be? | Direct holdings plus look-through exposure in funds | Sets a sensible position limit |
| Can I hold through a drawdown? | Emergency savings, time horizon, and a written response plan | Tests whether the position matches your risk capacity |
| What would change my mind? | Specific thresholds for renewals, margins, cash flow, competition, or execution | Prevents moving the goalposts after bad news |
Bottom line for a Costco portfolio decision
Costco’s FY2026 results describe a large, growing membership retailer with strong customer retention and disciplined pricing, but those facts are only the starting point. Decide whether COST fits by combining a multi-period operating review with a dated valuation analysis and a candid assessment of concentration and downside capacity. Recheck the next company disclosures, update the price and multiples, and make the position—if any—consistent with your broader financial plan rather than with the company’s reputation alone.
Quick wins for a faster PC:
Fix the driver behind crashes, sound loss and screen glitchesFind Drivers →Clear out junk files and repair common Windows errorsFree Scan →Quick Recap
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
