Even gold bars and silver coins couldn’t save Costco stock. The retailer’s shares closed down by more than 7% to roughly $725 per share on Friday, after it missed Wall Street’s earnings expectations the day before. That was Costco stock’s worst day in almost two years.

Costco’s declining stock performance comes just one day after the retailer posted its second quarter earnings for the 2024 fiscal year that ended Feb. 18.

The membership warehouse retailer pointed to an unlikely driver of success that quarter: E-commerce sales of gold and silver. That success however, may be short-lived, as Costco now looks to tackle concerns with the declining price of gasoline. Richard Gallanti, Costco’s chief financial officer, said that lower gas prices “negatively impacted total reported comp sales.”

“The average worldwide selling price per gallon of gas was down approximately 3.5% versus last year,” Gallanti, who will soon step down from the wholesale company, said.

Costco’s total comparable sales, excluding the fluctuation of gas and currency exchange rates, rose by 5.8%, highlighting that consumers are still on the hunt for deals from the 40-year-old membership-based retailer.

For the quarter, Issaquah, Washington-based Costco reported a net sale increase of 6% to $57 billion, with an additional $1.1 billion generated via its membership fees.