Upon reporting another quarter of poor earnings results, Macy's shares tumbled 15% on Wednesday afternoon, bringing the stock prices of its big-box competitors down with it.

This latest decline comes after a weak holiday season for the major retailers. Even as gas prices hit new lows and strong jobs numbers keep coming in, big-box retail suffers.

"We’re frankly scratching our heads,” Macy’s CFO Karen Hoguet told Wall Street analysts, Fortune reports. “We too are somewhat puzzled by the data that we’re seeing on the consumer, and the traffic we’re seeing in the stores and on the (web) site.”

Data released by eMarketer on Wednesday shows Amazon’s e-commerce revenue rose 15.8% over the past year to $82.7B. Although Walmart currently enjoys a similar growth rate for its e-commerce platform, Amazon has a much larger established base, and a $70.2B gap is not easily bridged. Although e-commerce is far from an insignificant portion of sales, major retailers still depend primarily on their brick-and-mortar stores. [Fortune]