Costco Wholesale Corporation (COST) — Coverage File

Data as of: FY2026 (52 weeks ended August 30, 2026); FY2026 10-K filed Oct 7, 2026; latest source Q4 FY2026 call, Sep 24, 2026 File last updated: October 10, 2026 (initial build)

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0. 30-second reopen

• Business: 939 membership warehouses selling fewer than 4,000 SKUs at an ~11% gross margin; 84.1M paid households pay $5.9B a year in fees, about half of the $11.7B operating income.
• Core debate: Is slowing member growth (3.8%) and a stalled renewal rate (89.8% worldwide) a normalisation after a digital sign-up surge, or the first sign that the membership annuity is compounding more slowly, at a price of ~46x earnings?
• Base thesis: The price gap keeps traffic growing, Executive upgrades deepen the fee stream, and ~30 net new warehouses a year are funded by operating cash flow and supplier credit, so earnings compound at low double digits for a long time.
• Main bear case: Not a broken business but a normalising one: fee-increase benefits lapped, member growth slowing, gas and inflation flattering comparable sales, SG&A leverage gone, capex rising faster than the warehouse count, all under a fast-grower's multiple.
• What to watch: Fee growth excluding increases and FX, paid-member growth and worldwide renewal, traffic, SG&A rate excluding gas, capex after FY2027, and the timing of the next fee increase.
• Valuation: ~$420B market cap, ~45.6x FY2026 diluted EPS, ~2.2$15B net cash (Oct 9, 2026 web price) — priced for many years of compounding with little room for a growth slowdown.

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1. Business snapshot

Costco operates membership warehouses in 14 countries: 939 at the end of FY2026, 774 with gas stations, plus e-commerce sites in nine countries and Costco Travel [FY2026 10-K]. The model is to sell a limited range of nationally branded and Kirkland Signature items in bulk at the lowest possible markup, turn inventory fast enough that suppliers are paid after the goods are sold, and charge an annual fee for access. FY2026 net sales were $297.2B (+10%) and membership fees $5.9B (+11%); operating income was $11.7B, a 3.9% margin on total revenue, and net income $9.2B ($20.76 per diluted share, +14%) [FY2026 10-K].

Sales come from core merchandise (foods and sundries, non-foods, fresh) and from ancillary and other businesses (gas, pharmacy, optical, food court, e-commerce, business centers, travel). Gas was 11% of net sales and digitally enabled sales 11% [FY2026 10-K]. The U.S. produced $219.8B of segment revenue and $7.6B of operating income, Canada $40.6B and $2.1B, Other International $42.8B and $1.9B; operations outside the U.S. earned 35% of operating income, and California alone is 26% of U.S. net sales [FY2026 10-K].

2. Core debate

The first question is whether the membership fee stream is compounding more slowly. Paid members grew 7.9%, 7.3%, 6.3% and then 3.8% over FY2023–26, and worldwide renewal fell from 90.5% (FY2024) to 89.8%, which Costco attributed to more memberships sold online [FY2025 and FY2026 10-Ks]. Management's answer is quality over count: Executive members grew 9.4% to 42.3M, renewal ticked up 10bp in Q4, and members under 40 now make up over a quarter of the base [Q4 FY2026 call]. Fees excluding the September 2024 increase and FX still grew 6.8% in Q4, but the increase stops contributing after Q4 FY2026 [Q4 FY2026 call].

The second is how much of the recent growth is core. FY2026 comparable sales were 8% reported and 7% excluding gas and FX, but traffic slowed from +5% in FY2025 to +3%, gas price inflation added 130bp to sales, and ancillary sales grew 20% against 8% for core merchandise [FY2026 10-K]. Even on 7% comparable sales, SG&A excluding gas did not leverage (+1bp) [FY2026 10-K]. At ~46x earnings, the debate is about duration, not quality.

3. Base thesis

Costco's advantage is a cost structure that rivals cannot copy piecemeal: a small assortment bought in enormous volume, no-frills buildings, short opening hours, cross-docking depots and labour productivity that comes from above-industry wages and ~94% retention of employees with at least a year of service in the U.S. and Canada [FY2026 10-K]. Low prices bring members; member fees cover about half of operating profit, which lets merchandise be sold at a margin less than two points above SG&A; and suppliers finance the inventory (accounts payable were 117% of merchandise inventory at FY2026 year-end, computed). The loop has compounded EPS at ~13% a year over FY2021–26 (computed) with a flat share count.

Assumptions this rests on:

1. Fee income grows at high single digits between fee increases, through sign-ups at new warehouses, Executive upgrades and renewal holding near 90% worldwide (89.8% FY2026) [FY2026 10-K].
2. Comparable sales excluding gas and FX stay around 6–7% with traffic, not inflation, leading (7% in FY2026; traffic +3%) [FY2026 10-K].
3. Costco reaches and holds ~30 net new warehouses a year for 5–10 years [Q4 FY2026 call] at returns close to the existing base, funded from operating cash flow.
4. Core-on-core gross margin holds or rises (+15bp FY2026) as supply chain gains and Kirkland Signature offset price investment [FY2026 10-K].
5. Digital, delivery, gas and pharmacy add share of wallet without weakening the warehouse visit.

4. Main bear case

The bear case is that Costco keeps executing while the numbers that justify the multiple normalise. FY2026 earnings growth of 14% was helped by the fee increase (about 30% of fee growth), non-recurring tariff refunds ($0.15 of Q4 EPS), interest income on a larger cash pile ($601M vs. $469M) and gas inflation [FY2026 10-K; Q4 FY2026 call]. Member growth has slowed for eight straight quarters (an analyst's count on the Q4 call; consistent with year-end counts), the CFO called the current rate "more typical" of what to expect, and capex is rising faster than openings: $4.7B, $5.5B, $6.4B and ~$7.5B planned over FY2024–27 against 29, 24, 25 and up to 28 net new warehouses [FY2024–FY2026 10-Ks; Q4 FY2026 call].

How it breaks: fee growth excluding increases falls to mid-single digits as online sign-ups churn and infill openings add few members; traffic slips below 2% once gas prices stop rising; wage increases (average U.S. hourly ~$33) outrun sales, so SG&A deleverages; and incremental warehouses in Europe and Asia, where members visit less often, earn less than the U.S. base. None of this breaks the franchise, but at ~46x earnings a slowdown to high-single-digit EPS growth is enough to cost years of returns through the multiple.

5. Business quality

Exceptional and durable. U.S./Canada renewal has stayed high and risen over time: 90% in FY2017, 91% in FY2021, 92.3% in FY2026 [FY2017, FY2021, FY2026 10-Ks]. Return on average equity was ~28% in FY2026 (computed), achieved with a net cash balance sheet and after paying special dividends of $10 (December 2020) and $15 (January 2024) per share [FY2021, FY2024 10-Ks]. Working capital is negative in the core: suppliers carried $22.6B of payables against $19.3B of inventory, and the gap widened in FY2026 on faster turns and better payment terms [FY2026 10-K].

Weak points: the margin structure leaves almost no room for error (a 10bp move in SG&A is ~$300M, ~2.5% of operating income, computed); profits are concentrated in the U.S. and Canada (83% of operating income) and in California (26% of U.S. net sales) [FY2026 10-K]; and the culture is a real asset that depends on management continuity, a risk the 10-K itself names under succession planning.

6. Key value drivers

Operating income = membership fees + (gross margin − SG&A) on merchandise. Fees: paid members (84.1M, +3.8%) × fee rate ($65 base, $130 Executive in the U.S.) × renewal (89.8$200M charge in FY2026), and SG&A per dollar of sales, dominated by wages and benefits [FY2026 10-K; Q4 FY2026 call]. Capital: capex per opening, depot and supply-chain spend, and supplier payment terms.

7. Financial profile

Sources: [FY2021, FY2024, FY2025, FY2026 10-Ks]. FY2021–26 CAGR (computed): net sales 9.1%, fees 8.8%, operating income 11.7%, EPS 13.0%.

FY2026 cash flow: operating cash flow $15.8B, capex $6.4B, free cash flow ~$9.4B (computed), dividends declared $2.5B ($5.54 per share; quarterly rate raised 13% to $1.47 in April 2026), buybacks $847M at an average $950.90 [FY2026 10-K]. Year-end cash and short-term investments $21.3B against $6.2B of debt ($2.2B current), so net cash ~$15.1B (computed); equity $35.8B; 443.3M shares outstanding, essentially unchanged on FY2025 [FY2026 10-K]. FY2026 also included $174M of IEEPA tariff refunds in merchandise costs, with $155M more received after year-end and the majority to be reinvested in prices [FY2026 10-K].

8. Valuation

Costco gives no long-term financial targets; its stated aims are ~30 net new warehouses a year and slower capex growth after FY2027 [Q4 FY2026 call]. At the October 9 close the shares trade at ~45.6x FY2026 diluted EPS and ~34.6x FY2026 operating income on an enterprise basis, with a ~2.2% free-cash-flow yield. Over FY2021–26 EPS compounded at ~13% (computed); the multiple therefore assumes something close to that rate continues for a long time, despite FY2026's growth containing a fee increase that will not repeat until the next one. Special dividends are the main capital-return lever, and ~$15B of net cash makes another one plausible (inferred; nothing announced in sources).

Market data (outside sources/, web, dated) Share price $946.92 at the Oct 9, 2026 close; market cap ~$419.6B; 443.13M shares outstanding; dividend $5.88 a year, 0.62% yield (stockanalysis.com, retrieved Oct 10, 2026). Derived by this file from filings: FY2026 diluted EPS $20.76, operating income $11.685B, free cash flow ~$9.4B, net cash ~$15.1B at Aug 30, 2026. Implied: ~45.6x FY2026 EPS, EV ~$404B, ~34.6x FY2026 operating income, FCF yield ~2.2%. In sources, the FY2026 average buyback price of $950.90 gives a similar ~45.8x [FY2026 10-K].

9. Management & capital allocation

Ron Vachris (CEO since January 2024, a career spent in Costco warehouse operations, merchandising and real estate) runs a team that is almost entirely promoted from within; the main outside hires are CFO Gary Millerchip (ex-Kroger, 2024) and CIO Javier Polit (2023) [FY2026 10-K; 2025 proxy]. The bench is turning over: in 2026 new COOs took over Merchandising, U.S./Mexico warehouse operations and the Northern Division, and Jim Klauer retires in October 2026 [FY2026 10-K]. The board left two seats vacant after Richard Galanti and Craig Jelinek retired [2025 proxy].

Capital allocation is conservative and consistent: reinvest in warehouses, depots and digital first, pay a growing regular dividend, return excess cash through occasional large special dividends rather than steady buybacks, and keep a net cash balance sheet. Pay is modest for the size of the company: CEO total compensation was $13.9M in FY2025, mostly performance RSUs [2025 proxy]. The performance bar is low, though: FY2025 grants required only a 3% increase in net sales or 2% in pre-tax income [2025 proxy]. Directors and officers as a group own ~460k shares (<1%) [2025 proxy]. Form 4 data is not in sources.

Claims to verify over time:

• Younger, digitally acquired members "grow into" higher spending and renewal [Q4 FY2026 call].
• Delivery-platform sales (Instacart, Uber Eats, DoorDash) are "mostly incremental" to the warehouse [Q4 FY2026 call].
• Capex growth slows after FY2027 [Q4 FY2026 call].

10. Risks ranked by damage

1. Valuation outrunning a normalising growth rate Damage rank: High · Permanence: High · Fixability: Low Mechanism: A ~46x multiple prices in years of ~13% EPS growth; if growth settles at high single digits, the multiple compresses even as the business performs. Evidence today: fee increase lapped after Q4 FY2026; paid-member growth 3.8%; tariff refunds and interest income flattered FY2026 [FY2026 10-K; Q4 FY2026 call]. What would confirm it: FY2027 EPS growth below ~10% excluding tariff items with no fee increase announced. Impact: a one-third de-rating at 9% EPS growth takes ~5 years to recover (computed).

2. Membership quality erosion Damage rank: High · Permanence: Medium · Fixability: Medium Mechanism: Online and younger sign-ups renew less; infill and Asian openings add fewer or lower-frequency members, so the fee stream (half of operating income) compounds more slowly. Evidence today: worldwide renewal 90.5% → 89.8%; member growth 7.9% → 3.8% over FY2023–26 [FY2024–FY2026 10-Ks]. What would confirm it: worldwide renewal below 89.5% or Executive growth below ~7%. Impact: slower growth in the highest-margin earnings stream; renewal by cohort is not disclosed.

3. Loss of SG&A leverage Damage rank: Medium · Permanence: Medium · Fixability: Medium Mechanism: Wage and benefit leadership (U.S. average hourly ~$33, top of scale +$1 in March 2026) needs strong comparable sales to stay neutral. Evidence today: SG&A excluding gas +1bp on 7% comparable sales; rose in Canada and Other International [FY2026 10-K]. What would confirm it: SG&A excluding gas up more than 10bp in a year. Impact: ~$300M of operating income per 10bp (computed).

4. Capital intensity rising faster than the store base Damage rank: Medium · Permanence: Low · Fixability: High Mechanism: Supply-chain and international build-outs raise capex per opening; new markets need years to mature. Evidence today: capex +59% FY2024–27 plan against a flat-to-rising opening count [FY2024–FY2026 10-Ks]. What would confirm it: capex still rising in FY2028 with operating income growing slower than invested capital. Impact: gradual erosion of the ~28% return on equity.

5. Channel shift to delivery platforms and AI search Damage rank: Medium · Permanence: Medium · Fixability: Medium Mechanism: Members ordering through Instacart, Uber Eats or DoorDash skip impulse non-foods, the food court and gas, and attach loyalty to a third party's app. Evidence today: delivery partnerships expanded nationwide; Costco Next marketplace closed; digitally enabled sales +21% [Q4 FY2026 call; FY2026 10-K]. What would confirm it: digital share rising while warehouse traffic growth falls below ~2%. Impact: lower margin per visit and weaker membership value perception.

6. Concentration and external shocks Damage rank: Low · Permanence: Low · Fixability: Medium Mechanism: California, tariffs, gas prices and FX move results. Evidence today: California 26% of U.S. net sales; ~$500M of IEEPA tariffs paid before refunds; gas 11% of sales [FY2026 10-K]. What would confirm it: a regional downturn or new tariffs without refunds. Impact: mostly cyclical and passed through over time.

11. Metrics to monitor

12. Thesis tripwires

13. Open questions

1. What is renewal by sign-up channel and age cohort? Costco blames online sign-ups but does not disclose the split.
2. When is the next fee increase? The last two were seven years apart (June 2017, September 2024) [FY2017, FY2024 10-Ks].
3. What do new warehouses earn, and how does Asia or Europe compare with the U.S.? No per-warehouse economics are disclosed.
4. How much of the 21% digital growth runs through third-party delivery platforms, and at what margin to Costco?
5. Will the $15B net cash be returned as a special dividend, as in 2020 and 2024?

14. Update log

15. Source map