Comparable traffic rose 7.2%, including a 7.4% increase in the U.S. And while Costco reported solid growth around the world, its domestic business continued to lead the way with a 10% comp sales gain last month. Costco deepens its moat Inflation has started to heat up this year, due to a combination of factors including a shortage of shipping capacity, pandemic-related production losses, and high demand. Last month, Costco Wholesale (NASDAQ: COST) reported stellar results for the final quarter of its 2021 fiscal year.