BENTONVILLE, Ark. (KNWA/KFTA) — After Walmart released mixed quarterly results on May 17, the Bentonville-based retailer’s stock fell by over 11%.

The decline was Walmart stock’s worst single-session performance since 1987. Volume was high on the day, with over 44 million shares changing hands.

Earlier in the day, Walmart announced first-quarter adjusted earnings of $1.30 per share, falling below the expected mark of $1.48.

While sales remained strong in the first quarter, the nation’s largest retailer saw profits dip due to inflation on food and fuel, as well as higher supply chain costs.

“Bottom line results were unexpected and reflect the unusual environment, “said CEO Doug McMillon. “U.S. inflation levels, particularly in food and fuel, created more pressure on margin mix and operating costs than we expected.”

Walmart is among the first major retailers to report quarterly results and is considered a major barometer of spending given its size and the breadth of its customer base.