Costco released a solid set of figures for its fiscal 2026 third quarter last week. For the period ended May 10, the company's total revenue reached $70.53 billion, which includes membership fees, marking a 11.6% year-over-year increase and surpassing market expectations of $69.62 billion.

Net income was $2.19 billion, or $4.93 per share. Global comparable sales grew by 9.8%, accelerating from the 7.4% growth seen in the previous quarter, with U.S. sales up 9.4% and international sales rising 11.2%. Membership fee income increased by 10.7% to $1.37 billion, with the global renewal rate holding at a historically high level near 90%, and the U.S. and Canada region reaching an impressive 92.2%.

However, following the earnings report, the stock faced some downward pressure due to margin pressures from record-high gasoline sales and certain membership growth metrics falling short of expectations.

What truly makes the market cautious about the company is likely its elevated valuation. Data shows that Costco currently trades at a forward price-to-earnings ratio of approximately 51 times, with a forward P/E ratio around 46 times.

While the company possesses unparalleled member loyalty and resilience across economic cycles within the retail sector, this valuation level demands that it must deliver near-perfect growth for several consecutive quarters in the future. Some analysts estimate its fair value to be around $726, whereas the current stock price remains above $950, implying an overvaluation of roughly 31%.

Institutions adopting a cautious stance have cited valuation concerns. Several firms, including Guggenheim and DA Davidson, have recently opted for a "wait-and-see" approach, maintaining "Hold" ratings on the stock.

A Guggenheim analyst noted that Costco is the most highly valued large consumer staple company in their coverage, and while some concerns regarding margins and membership growth may be temporary, this does not alter the view that the stock's upside potential is limited.

From a technical perspective, the stock has retraced about 10% since hitting a record high in May, indicating market profit-taking after the earnings season and deeper concerns about whether the high valuation can be fully justified by future performance.

Current Wall Street consensus remains a "Moderate Buy," with an average price target around $1,105, suggesting a theoretical upside of approximately 16%.

However, for Costco, its robust business model and highly predictable earnings are already fully priced into the market.

As one analyst remarked, the current price level has already discounted growth for many years ahead, meaning that even a slight downward revision in expectations could trigger significant volatility, amplified by the leverage effect of its high valuation.