Costco August Same-Store Sales Rise 5.4% as Membership Growth Slows
Costco reported a 5.4% increase in overall same-store sales for the four weeks ended August 30, excluding gasoline price and currency fluctuations, though the figure was dragged by 0.75 percentage points due to a later Labor Day. Membership growth slowed, with online sign-ups showing lower renewal rates. Shares traded flat at $929, down 15% from their May record.
Costco released its sales data for the four weeks ended August 30 on Wednesday evening. Excluding the impact of gasoline prices and currency fluctuations, overall same-store sales rose 5.4% year over year. The figure was dragged by 0.75 percentage points because Labor Day fell one week later than in the prior year. Same-store traffic growth slowed by 1.1 percentage points, below the average pace of the past 12 months.
Costco shares traded flat on Thursday at $929, down 15% from the record high of approximately $1,097 set in May. The stock has gained about 8% so far in 2026. After failing to hold its 2026 highs, the share price has followed a pattern of volatility similar to that seen in 2025.
The majority of Costco's operating income comes from membership fees. The company has seen a slowdown in membership growth, with online registrants tending to be younger and showing lower renewal rates than those who sign up in stores. The company has consistently delivered mid-single-digit to high-single-digit same-store sales growth over the years. The August sales report marks the end of fiscal 2026, and the company is scheduled to report its latest quarterly earnings later this month.