Costco reports higher revenues and net income in Q3

Costco delivered solid Q3 results, with total revenue up 11.6% to $70.52bn, net sales up 11.6% to $69.15bn, and net income rising to $2.19bn from $1.90bn a year ago. For the first 36 weeks of fiscal 2026, revenue increased to $207.43bn and net income to $6.22bn, while digitally enabled comparable sales jumped 21.5% in Q3 and 21.6% year to date. The print highlights continued strength in membership fee income, comparable sales, and digital demand.

Analysis

The signal is less about a clean traffic beat and more about Costco widening the gap between top-line growth and the rest of retail. That combination usually forces weaker club, grocery, and value-channel peers to compete harder on price while absorbing higher fulfillment and labor costs, so the second-order loser set is broader than the headline suggests: Sam’s Club, BJ’s, grocery chains, and lower-income exposed discretionary retailers. The digital acceleration matters because it is not just an e-commerce story; it improves customer frequency and basket stickiness while making it harder for peers to dislodge members once they’ve loaded the app into their weekly routine.

The key risk is that Costco’s model can look deceptively durable right up until input inflation or wage pressure compresses the margin mix. Membership revenue is the real quality signal here, but it also creates a valuation trap: if the market extrapolates this quarter into perpetuity, the stock can become vulnerable to even a modest deceleration in comp ex-gas/FX over the next 1-2 quarters. In that scenario, the multiple will likely de-rate before the P&L does, because the market is paying for consistency, not upside surprise.

The most interesting contrarian angle is that strong reported growth may actually pull forward demand from the next several quarters, especially in categories where consumers stock up when they feel confident. If household balance sheets soften later in the year, Costco can still hold relative share, but absolute growth may normalize faster than consensus models imply. That sets up a cleaner long/short than an outright directional long, because the company can remain fundamentally excellent while the stock underperforms if expectations get too aggressive.

Key Decisions for Investors

• Long COST / short a basket of lower-quality value retail and grocery exposure for 3-6 months; the thesis is share migration toward scaled operators with higher member loyalty and better digital engagement. Risk is a broad consumer rebound that lifts all boats, but the pair should still work if relative gross margin discipline stays intact.
• If COST rallies into the next print, look to buy downside protection via 1-3 month puts or put spreads rather than selling the stock outright. This is a good setup for a valuation air-pocket if comps revert even modestly, with limited carry cost versus the downside if the market starts discounting normalization.
• Initiate a tactical short in BJ or a relative short versus COST over the next quarter if you want direct exposure to competitive pressure in the warehouse club channel. Costco’s scale and digital momentum make it the cleaner compounder, while smaller peers are more exposed to margin squeeze and member acquisition costs.
• For long-only portfolios, hold COST on pullbacks, not breakouts. The risk/reward is best after any 5-8% post-earnings digestion, when the market has time to reset expectations but the fundamental trajectory remains intact.