Costco looks like a retailer.
Economically, it behaves more like a membership network with warehouses attached.
The company keeps merchandise margins deliberately thin, gives much of its purchasing advantage back to members, and earns their loyalty in return.
That is why comparing Costco with an ordinary grocer misses the point.
It is also why paying any price for the stock is dangerous.
At $922.23, investors are not debating whether Costco is a great business.
They are debating how much of that greatness is already capitalized.
What Costco actually controls
Costco controls a high-trust loop.
Limited assortment creates purchasing power. Low markups create visible value. Visible value drives traffic and renewals. Renewal income lets Costco keep markups low.
The loop is difficult to copy because every piece reinforces the others.
In fiscal 2026, net sales rose 10.1% to $297.2 billion and diluted EPS increased to $20.76 from $18.21.
Adjusted comparable sales rose 6.6%, while digitally enabled comparable sales increased 20.7%.
Why does that matter?
Costco is growing traffic, ticket, digital engagement, and warehouse count without abandoning the value proposition that created the moat.
Business quality versus stock valuation
The quality is visible in membership behavior.
Costco ended fiscal Q4 with 84.1 million paid memberships, 150.4 million cardholders, and 42.3 million Executive memberships.
Renewal rates were 92.3% in the U.S. and Canada and 89.8% worldwide.
This is recurring revenue earned through trust rather than contractual lock-in.
But fiscal 2026 EPS included a $0.15 benefit from tariff refunds, and the retail gross margin was only about 11% in the fourth quarter.
Costco is resilient, not invulnerable.
What $922.23 requires
I use fiscal 2031 as the checkpoint and an 8.8% required annual return over five years.
That hurdle starts with the 5.11% 10-year Treasury yield, adds the 4.14% implied U.S. equity risk premium, and uses a 0.90 bottom-up beta for a defensive, low-leverage retailer.
At a 35 times terminal earnings multiple, today's price requires roughly $40.20 of fiscal 2031 EPS.
That means EPS must nearly double from fiscal 2026 while the stock still deserves a premium multiple five years from now.
The business can plausibly do the first.
The valuation needs both.
Three possible outcomes
Conservative: about $590 today
Costco earns $30 per share in fiscal 2031 and receives a 30 times terminal multiple.
Traffic remains healthy, but wage investment and merchandise costs limit margin expansion.
The company compounds.
The multiple normalizes.
Base case: about $918 today
Costco earns $40 per share in fiscal 2031 and receives a 35 times terminal multiple.
Membership, international warehouses, digital sales, and modest margin improvement compound together.
That outcome is almost exactly the checked price.
Upside case: about $1,311 today
Costco earns $50 per share in fiscal 2031 and receives a 40 times terminal multiple.
This requires exceptional execution, faster international growth, and a market still willing to value Costco unlike almost every other retailer.
At $922.23, the stock is priced for an excellent base case.
Capital intensity and valuation risk
Costco must keep opening warehouses, investing in logistics, paying employees well, and protecting price leadership.
Those are productive investments, but they require capital and discipline.
The larger risk is valuation compression.
A company can beat expectations and still produce a weak return if investors begin with too high a multiple.
That is the uncomfortable part of Costco.
The business does not need to break for the stock to disappoint.
What to watch out for
- Membership renewal and paid-member growth - because the membership relationship is the moat.
- Executive-member penetration - because higher-spending households deepen the economics of the network.
- Traffic versus ticket growth - because real visit growth is healthier than inflation alone.
- Membership-fee growth after the 2024 price increase laps - because normalized growth matters more than the temporary step-up.
- Gross margin and SG&A - because Costco must fund employee and member value without weakening earnings leverage.
- New warehouse returns, especially internationally - because the next leg of growth must remain productive.
What could change the thesis
The thesis would strengthen if EPS approaches the $40 hurdle faster than expected while renewal rates and traffic remain strong.
The thesis would weaken if renewal rates weaken, traffic slows, or the stock retains a premium multiple while earnings estimates flatten.
The disconfirming evidence would be a great membership business producing ordinary per-share growth.
Bottom line
Costco is one of the highest-quality retailers in the world.
Business quality: exceptional.
Balance-sheet and execution risk: manageable.
Valuation risk: high.
At $922.23, Costco can deliver a satisfactory return, but it needs both strong earnings growth and a premium terminal valuation.
The practical principle: the better the business, the easier it is to forget that the price is still part of the investment.
Sources
- Costco fiscal Q4 and full-year 2026 results
- Costco fiscal Q4 2026 supplemental presentation
- Costco fiscal Q3 2026 Form 10-Q
- Federal Reserve H.15 interest rates
- Damodaran U.S. industry betas
- Damodaran implied equity risk premium
Scenario values are analytical estimates, not company guidance or price targets. Educational only - not financial advice.