We note that shares of Costco have climbed roughly 4.3% year to date, and has comfortably outperformed the Zacks categorized Retail-Discount & Variety industry's decline of 3.3%. Excluding the impact of foreign currency fluctuations and gasoline prices, Costco's comps for the month under review rose 5%. Costco Wholesale CorporationCOST has continued to post positive comparable-store sales (comps) so far this year.