What was Costco's same-store sales growth in Q3 2026?

Same-store sales increased 6.5% year-over-year.

Why did Costco stock fall despite strong results?

The stock may have been overvalued, or investors expected even higher growth.

Did Costco provide guidance for the next quarter?

No specific quarterly guidance was given, but the company indicated ongoing investment in expansion.

Costco Stock Dips Despite Strong Same-Store Sales Growth in Q3

Costco reported strong fiscal Q3 2026 results with same-store sales up 6.5%, yet the stock dipped. We analyze the key numbers and why investors weren't impressed.

Costco Wholesale (COST) reported robust fiscal third-quarter 2026 results, with same-store sales surging 6.5% year-over-year, beating expectations. However, the stock failed to gain traction, edging lower in after-hours trading.

Key Financial Results

Metric	Q3 2026	YoY Change
Revenue	Not yet disclosed	-
Net Income	Not yet disclosed	-
EPS	Not yet disclosed	-
Same-Store Sales	+6.5%	-

Note: Detailed financial figures have not been released yet.

Highlights from the Report

Costco attributed the sales growth to increased foot traffic and strong discretionary spending, particularly in fresh food and home categories. Membership expansion also contributed to revenue growth.

Guidance

Costco did not provide specific quarterly guidance but indicated continued investment in international expansion and e-commerce improvements.

Stock Reaction

Despite the positive results, Costco stock (COST) fell 0.8% in after-hours trading, suggesting investors had priced in even higher growth or that the stock was already fully valued.

What This Means for Investors

Costco remains one of the strongest retailers due to its unique membership model and loyal customer base. However, its high valuation may limit near-term upside, especially if margins do not improve.