⚠ A Store Holds One of EverythingModerate threat

Walmart (WMT) — threat to the moat

Cheap because the inventory is already there, and limited for exactly the same reason.

The store-fulfilled model is cheap because the inventory is already there. It is limited for exactly the same reason: a supercenter stocks a shop's worth of depth, not a warehouse's.

Where the growth sits, June 2026 quarterMarketplace sales (third-party inventory)+52%Store-fulfilled delivery (Walmart inventory)~+43%Walmart U.S. eCommerce+24%Global eCommerce+23%Expedited orders under three hours~37% of store-fulfilledMarketplace inventory does not sit in a Walmart store.
The fastest-growing part of Walmart's digital business is the part the store estate cannot fulfil, because a shop holds one of most things and a warehouse holds forty.

That constraint bites in two directions. A picker who finds the shelf empty substitutes or shorts the order, which is a worse experience than a warehouse would deliver and is invisible in any disclosed metric. And the assortment a customer can actually order for three-hour delivery is bounded by what one building holds — which is why the growth of Walmart's online selection depends on marketplace sellers and on dedicated fulfilment, not on the stores at all.

The tension is structural. The broader Walmart's online assortment becomes, the smaller the share of it the stores can serve, and the more the company has to build or rent capacity that has none of the sunk-cost advantage the stores have. Marketplace sales grew 52% in the June 2026 quarter1 — far faster than eCommerce overall at 23% — and almost none of that inventory sits in a Walmart store.

There is also a competitive asymmetry worth naming. Amazon's network was designed for parcels and holds forty of an item where a store holds one; it loses on the last four miles and wins on depth. Walmart's answer has been speed on the items people reorder, which is a real and defensible position, and a narrower one than the marketing suggests.

Watch the gap between marketplace growth and store-fulfilled delivery growth — 52% against roughly 43% in the June quarter23. If marketplace keeps pulling away, the mix of Walmart's digital business is shifting toward the part the store estate cannot fulfil.

References
  1. ReportedMarketplace sales grew 52% in the June 2026 quarter — far faster than eCommerce overall at 23% — and almost none of that inventory sits in a Walmart store.
    Walmart second-quarter fiscal 2027 earnings presentation (Form 8-K exhibit 99.2) - Walmart U.S. comp sales +2.6% with transactions excluding fuel +1.5% and average ticket excluding fuel +1.1% against total like-for-like inflation of 1.4%, and an approximately 125 basis point pharmacy headwind from maximum fair price regulation; eCommerce +24% including approximately 43% growth in store-fulfilled delivery, total advertising +38% including Walmart Connect +43%, and Marketplace sales +52%; expedited deliveries under three hours approximately 37% of store-fulfilled orders; share gains across categories and income tiers led by upper-income households — Q2 FY2027 · publ. August 20, 2026 · source ↗
  2. ReportedWatch the gap between marketplace growth and store-fulfilled delivery growth — 52% against roughly 43% in the June quarter.
    Walmart second-quarter fiscal 2027 earnings presentation (Form 8-K exhibit 99.2) - Walmart U.S. comp sales +2.6% with transactions excluding fuel +1.5% and average ticket excluding fuel +1.1% against total like-for-like inflation of 1.4%, and an approximately 125 basis point pharmacy headwind from maximum fair price regulation; eCommerce +24% including approximately 43% growth in store-fulfilled delivery, total advertising +38% including Walmart Connect +43%, and Marketplace sales +52%; expedited deliveries under three hours approximately 37% of store-fulfilled orders; share gains across categories and income tiers led by upper-income households — Q2 FY2027 · publ. August 20, 2026 · source ↗
  3. ReportedWatch the gap between marketplace growth and store-fulfilled delivery growth — 52% against roughly 43% in the June quarter.
    Walmart second-quarter fiscal 2027 earnings presentation (Form 8-K exhibit 99.2) - Walmart U.S. comp sales +2.6% with transactions excluding fuel +1.5% and average ticket excluding fuel +1.1% against total like-for-like inflation of 1.4%, and an approximately 125 basis point pharmacy headwind from maximum fair price regulation; eCommerce +24% including approximately 43% growth in store-fulfilled delivery, total advertising +38% including Walmart Connect +43%, and Marketplace sales +52%; expedited deliveries under three hours approximately 37% of store-fulfilled orders; share gains across categories and income tiers led by upper-income households — Q2 FY2027 · publ. August 20, 2026 · source ↗
Sources
Generated September 22, 2026