Costco Has Grown Its Membership Base no Matter What the Economy Has Done. Does That Make It a Forever Hold?

Costco’s paid memberships rose to 58.1M in fiscal 2020 (from 53.9M) and have climbed every year to 82.9M through fiscal Q3 2026, with renewal rates consistently near/above 90%. Despite the durable, low-margin (net profit margin ~3%) membership model, the stock is valued at ~47x trailing earnings versus ~30x historically, while Wall Street expects ~11% annual growth—raising risk of underperformance if the P/E mean-reverts.

Analysis

COST is still a high-quality defensive compounder, but the market is paying for near-flawless execution, which leaves the stock more exposed to multiple compression than to any near-term earnings miss. The key mechanism is duration: when a retailer trades like a bond proxy, the P/E becomes more sensitive to real-rate moves and factor rotation than to another quarter of steady memberships. That makes the stock vulnerable even if the operating story stays intact.

Second-order, a slower re-rating in COST can redirect incremental capital toward lower-multiple defensives with better near-term upside, especially WMT and BJ, where valuation support is stronger if consumer trade-down persists. For suppliers, COST’s buying power continues to pressure gross margins and mix, but that is already well understood; the underappreciated risk is that fee-driven growth saturates, leaving earnings reliant on modest traffic and ticket gains rather than a fresh step-up in customer acquisition. In that setup, any macro relief rally may bypass COST because the market is already assuming resilience.

The contrarian view is that the business quality is not the issue; the question is whether renewal stability is now fully monetized in the stock. If same-store sales or membership-fee monetization accelerates, the multiple can hold, but absent a clear catalyst the setup favors waiting for a cheaper entry. Near term, a backup in rates or a broad rotation out of expensive defensives is the cleanest path to underperformance over the next 1-3 months; over 6-18 months, the risk is simply mean reversion in valuation rather than a fundamental break.

Key Decisions for Investors

• Avoid initiating fresh long COST here; wait for either a 10-15% drawdown or evidence of a fee-driven earnings reacceleration before buying. Risk/reward is poor while the stock trades on a premium multiple with limited near-term upside.
• Pair trade: short COST / long WMT or BJ on a 1-3 month horizon. The thesis is valuation convergence, with the long leg anchored by lower multiple and more room for operating upside; cut the trade if COST outperforms on a rate decline or if WMT/BJ guidance weakens.
• If you need defensives, rotate into XLP or WMT rather than owning COST outright. This captures retail defensiveness without paying the full quality premium that can compress if real yields rise.
• Set an alert for any meaningful increase in membership-fee growth or an explicit upgrade to forward earnings growth. That would be the clearest falsifier of the de-rating thesis and would justify covering any COST short exposure.