The price of goods has remained stagnant in recent years, thanks in part to a combination of low commodity prices and rising food prices.
Costco is the No. 2 retail price-gouging brand, according to the Consumer Reports brand ranking.
Walmart is No. 3.
Costco also leads in grocery delivery services and the price of some of its food.
The grocery store giant said its annual report on November 2, 2018, showed a 13.5 percent increase in net income in the second quarter.
Walmart said its first-quarter profit rose 14.3 percent to $3.3 billion.
Walmart’s first-half profit was down 10 percent to just $1.1 billion.
But Walmart said it had also earned $2.7 billion in profit on its sales of products and services to its customers.
Costco said its profit jumped 28 percent to nearly $5 billion, while Walmart said revenue rose 20 percent to almost $1 trillion.
Both companies said their profits are the best they’ve ever been in their companies’ history.
Walmart and Costco both reported profits that were lower than last year.
Walmart was the worst-performing retailer of the two.
It reported a $1 billion net loss in the quarter, while Costco had $3 billion in revenue.
Walmart shares closed up 2.5 cents at $61.82 in midday trading.