Costco Wholesale (NASDAQ:COST) shares were trading more than 4% lower intra-day today after the company reported net sales of $21.71 billion for the retail month of March, which represents an increase of just 0.5% from a year-ago period.

Comparable sales were down 1.1%. This decline was partly due to a decrease in gasoline prices, but even after taking that into account, comparable sales did not keep up with inflation, only increasing by 2.6% over the year. In contrast, consumer prices had risen by 6% in March.

The U.S. saw a significant slowdown in sales, with an increase of only 0.9% from the previous year. However, sales in Canada went up by 7.4%, and sales in other parts of the world increased by 7.6%.