Costco shares were down $2.23, or just under 1%, at $243.38 in premarket trading on the Nasdaq Stock Market. They ended the trading day Thursday at $245.61.
Costco said its net sales rose 7.4% in March to $13.87 billion from a year earlier, while same-store sales rose 5.7%, or 5.9% when excluding gas prices, foreign exchange rates, and new accounting standards.
However, this year's five-week March retail month with one extra shopping day vs. last year beefed up total and comparable sales by "one to one and one-half percent," Costco said.
The company announced in June it was raising its minimum wage to $14 from $13 an hour.