Yet despite that success—Walmart’s U.S. business saw e-commerce grow 79%, making it the No 2 online retailer in 2020—the big box store remains far behind its longtime rival, Amazon, and will continue to be so this year, according to a forecast released on Monday by eMarketer.

The research firm expects Amazon to ring in sales of $367.2 billion this year, nearly six times more than the $64.6 billion it forecasts Walmart U.S. will rake in. What’s more, eMarketer expects Amazon, which already generates almost 40% of all e-commerce stateside, to win more market share.

Walmart has hardly been idle in its battle with Amazon. It has launched an express delivery service for groceries, one area of e-commerce where it has a clear upper hand over Amazon, as well as Walmart+, a subscription service similar to Amazon Prime.

“We’ve got a unique opportunity because of our stores. We’ve got all of the things available to us related to eCommerce growth,” Walmart CEO Doug McMillon told Wall Street last month.

Despite Amazon’s growing dominance, a number of big box stores thriveD during the pandemic. Target, for one, saw e-commerce more than double last year, helped by its popular store brands and vastly improved grocery offering that curbside delivery for those wary of going into stores made easier to buy.

Kroger, despite its massive size, is still not a Top 10 U.S. e-retailer, but eMarketer thinks that changes this year. In 2020, Kroger benefited enormously from its partnership with tech firm Ocado, whose automation and artificial intelligence, make the grocer much better at filling online order.

In contrast, Macy’s, long on the Top 10 list fell out of the list last year and isn’t likely to return. The department store’s e-commerce business is formidable but the pandemic set it back very far.

Best Buy and Home Depot, two of the pandemic’s big retail winners, are also expected to have strong years online.