Costco Wholesale Corporation (COST)

One-line summary: Membership warehouse retailer; Q3 FY2026 delivers corroborating evidence across four active theses: all-time gas volume records (Hormuz), pharmacy market share gains from GLP-1 demand (Wegovy/Ozempic), memory chip cost headwinds at retail electronics, and AI search triple-digit growth with highest conversion rate.

Role / thesis relevance

Costco serves as an independent consumer-channel corroborator across multiple active mechanisms due to the breadth and specificity of its CFO/CEO commentary. With 82.9M paid members and $69.2B in Q3 FY2026 net sales, the company's operational data is a high-signal, low-noise indicator of macro trends at consumer level.

Key claims

• ron-vachris in 2026-05-28-earnings-cost-q3-fy2026: "All 3 4-week fiscal periods of the quarter set successive all-time company volume sales records, with the final 5 weeks of the quarter becoming our top 5 volume weeks ever." [gasoline, Hormuz-period]
• gary-millerchip in 2026-05-28-earnings-cost-q3-fy2026: "higher cost of memory chips in computers having an impact on the sort of cost of items in majors" [DRAM pass-through]
• gary-millerchip in 2026-05-28-earnings-cost-q3-fy2026: "Pharmacy led the way and saw significant market share gains in the quarter. In addition... factors... include increased GLP-1 demand, and inclusion of Wegovy and Ozempic in our Member Prescription Program" [GLP-1]
• gary-millerchip in 2026-05-28-earnings-cost-q3-fy2026: "triple digit growth in Q3, and this activity had the highest conversion rate of all traffic coming to our site" [AI search]
• From 2026-09-25-costco-cost-q4-fy2026-earnings-release-8-k-exhibit (8-K exhibit 99.1, 16 weeks ended Aug 30, 2026): net sales $93.873B (+11.2%); membership fees $1.850B; diluted EPS $6.75 vs $5.87, including a non-recurring $0.15 IEEPA tariff-refund benefit less partial reinvestment in member values; total-company comps +9.4% (+6.7% ex-gas/FX); digitally-enabled comps +19.5%; worldwide membership renewal 89.8%; 939 warehouses (647 US). Kirkland price cuts (walnuts $13.79→$9.99) are retailer-captured PL, not a listed manufacturer. Do not graduate COST.

Key metrics (Q3 FY2026)

• Net sales: $69.2B (+11.6% YoY)
• EPS: $4.93 (+15%)
• Traffic: +2.4%; ticket: +7.3%
• Total paid members: 82.9M
• AI search: triple-digit growth, highest site conversion rate

Key personnel

• ron-vachris — President & CEO, Costco
• gary-millerchip — CFO, Costco

Related

• energy-shock-2026-vs-2022 — all-time gas volume records during Hormuz shock
• glp1-injectable-supply-chain-bottleneck — pharmacy GLP-1 market share gains
• hbm-cowos-as-binding-bottleneck — memory chip cost pass-through at retail
• ron-vachris
• gary-millerchip

Sources

• 2026-05-28-earnings-cost-q3-fy2026 — Q3 FY2026 earnings; gas records, GLP-1 pharmacy, DRAM pass-through, AI search
• 2026-09-25-costco-cost-q4-fy2026-earnings-release-8-k-exhibit — Q4 FY2026 8-K 99.1; comps +9.4%; $0.15 IEEPA refund; Kirkland price cuts retailer-captured