Costco's Cooling Comp Sales Keep Stock Stuck in Neutral for Now

Costco's June comparable sales decelerated from May as fading gas price tailwinds and weakening international, especially Canadian, comps offset strong headline net sales growth.

Costco trades at roughly 46 times forward earnings, more than double the retail sector average, making the stock vulnerable to any slowdown in comp sales growth.

Costco shares have fallen about 15% from their all-time high and now show bearish technical signals, though long-term fundamentals like renewal rates remain strong.

Costco Wholesale Club Inc. NASDAQ: COST recently reported its June sales numbers, and on first glance, it appears to be another strong month of growth for the country’s premier wholesale club. However, the stock’s milquetoast reaction shows how much of a curve the company is graded upon.

When your multiple looks more than a tech sector growth darling than a big box retailer, ‘good’ simply isn’t good enough. And when you dig under the surface, the latest sales numbers highlight an unnerving trend.

Costco released its comp sales figures for June, and it's a print that many other retailers would view with envy. Net sales for the period totaled $29.24 billion, up 10.6% year-over-year (YOY) and 7.6% when removing gas and currency effects.

The board also declared a $1.47-per-share dividend, payable in August with a record date of July 24.

But despite these strong headline numbers, weakness is brewing under the surface.

Gas price volatility was a major tailwind for Costco as weary consumers turned to wholesale clubs for relief at the pump. Costco typically prices its gas below retail to drive volume and get more people into its stores (also known as a loss leader). But now that gas prices are dropping again, this tailwind is evaporating, and the June sales print tells the tale.

When stripping out gas and currency, the 7.6% U.S. comp number is a stark deceleration from May’s 8.7% comps ex-gas and currency. The total drop is actually even steeper; 8.8% in June versus 12.5% in May, highlighting just how much fuel prices drove the advance.

U.S. stores might be in good shape, but the international market is a growing concern. Canadian adjusted comps plummeted again from 7.6% in April to 5.6% in May to 4.9% in June, and total international adjusted comps dropped from 8.0% in May to 7.0% in June.

Soft international markets could limit upside if U.S. comp sales reaccelerate, now that fighting has resumed in Iran and gas prices are once again on the upswing.

Costco remains an excellent business with a loyal membership base, strong overall sales growth (net sales up 11.6% YOY as of May’s fiscal Q3 2026 report), and a hot dog-and-soda combo that still costs just $1.50.

But the stock has long been priced to imply perfect execution, and when you trade at 46 times forward earnings with a Price/Earnings Growth (PEG) ratio nearly at 4.5, investors take notice of any little dent in the armor.

The retail sector trades at about 21 times earnings, which is less than half the current valuation bestowed on COST shares.