Costco Q3 US adjusted comparable sales growth?

Resolution Criteria

This market will resolve according to Costco's announced US adjusted comparable sales growth for the third fiscal quarter of 2026, as reported in its official company earnings materials. For the purposes of this market, US adjusted comparable sales growth refers to comparable sales growth excluding the impact of gasoline prices and foreign exchange, as reported by Costco in its official earnings materials. The specified metric will be considered as reported in the company's official earnings materials. Subsequent revisions will not be considered. If the specified company's official earnings materials for the specified quarter are released, and the specified metric is not included, this market will resolve to the lowest bracket. If the specified company does not release quarterly earnings materials for the specified quarter by June 30, 2026, 11:59 PM ET, this market will resolve to the lowest bracket. If the reported value falls exactly between two brackets, this market will resolve to the higher range bracket. If the specified metric is reported as a range rather than a specific number, the midpoint of the range will be used for resolution of this market. The resolution source for this market is Costco's official company earnings materials, including press releases, investor presentations, and regulatory filings. If the specified metric is not reported in these materials, recordings or transcripts of the company's earnings webcast may also be used. Note: This market will resolve based on the most numerically precise version of the specified metric reported in the company's official earnings materials. Only the US adjusted comparable sales growth figure excluding gasoline prices and foreign exchange will be considered; alternate versions that differ in definition or scope from the specified metric will not be considered.

Costco's US adjusted comparable sales growth for fiscal Q3 2026 — excluding gasoline prices and foreign exchange — is the subject of this prediction market, with volume heavily concentrated on the 6.5%–7.5% bracket as the heaviest-backed outcome. A secondary cluster sits at 4.5%–5.5%, suggesting the market sees a wide but bounded range of plausible results. Resolution is based on Costco's official earnings materials, with a deadline of 28 May 2026.

Market structure

Six bracketed outcomes span sub-4.5% to 8.5% and above. Volume is heavily concentrated on the 6.5%–7.5% range, making it the standout outcome by implied weight. The 4.5%–5.5% bracket commands a meaningful secondary share. The remaining four brackets are broadly distributed at much lower levels. Resolution uses the most numerically precise figure from Costco's official earnings materials; the lowest bracket serves as fallback if earnings are not released by 30 June 2026.

Background

Costco Wholesale reports comparable sales figures on a quarterly basis as part of its standard earnings disclosures, with the fuel- and exchange-adjusted US figure serving as a widely watched gauge of underlying retail momentum. Fiscal Q3 2026 covers the February–April period, a window that typically captures post-holiday consumer spending patterns and any shifts in membership-driven traffic. Costco has delivered consistent comparable sales growth over recent years, supported by its membership model, private-label expansion under the Kirkland Signature brand, and a broad grocery offering that has proved resilient across varying economic conditions. The adjusted figure strips out fuel price volatility — which can distort headline numbers significantly — to give a cleaner read on core retail performance. Investors and analysts monitor this metric closely as a proxy for member engagement and wallet-share trends.

Key factors

Several structural forces bear on where the adjusted comparable sales figure ultimately lands. Consumer spending patterns during the February–April window are shaped by tax refund timing, post-holiday normalisation, and any broader shifts in discretionary versus essential spend. Membership fee income and renewal rates influence traffic assumptions but do not directly enter the comparable sales calculation. Costco's ongoing investment in food courts, pharmacy, and optical departments diversifies the transaction base, but changes in category mix can shift the reported figure. Competitive dynamics from rival warehouse clubs and online grocery platforms affect basket size and visit frequency. Macroeconomic variables — including employment trends, consumer confidence, and real wage growth — influence how frequently members visit and how much they spend per trip. Because gasoline and foreign exchange are explicitly excluded, domestic pricing decisions and product assortment in US clubs are the primary levers. Any unusual weather events, supply chain disruptions, or promotional calendar shifts in the quarter could also push the figure toward the edges of the distribution.

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