While consumers may be letting their foot off the gas of the all-out panic shopping that marked the early days of the coronavirus pandemic, the race to stock up meant Walmart (WMT -0.35%) saw massive sales increases over the last four- and eight-week periods.

The Wall Street Journal reports internal documents show sales surged 20% during the month of March and spiked 30% since the beginning of February, compared with the same period a year ago.

A black and white image of crowded grocery store checkout lines

Image source: Getty Images.

We're all preppers now

As the largest U.S. grocery retailer with almost 4,800 stores in the U.S. generating some $341 billion in annual revenue, Walmart realized huge gains from being able to stay open during the crisis, but other large retailers with a broad footprint also saw a wave of panic buying in their stores.

Target (TGT -0.67%), for example, also witnessed a 20% jump in same-store sales over the four-week period ending March 25, though it mostly came from food and household goods while apparel sales declined.

Nielsen data indicates consumer goods sales were up over 21% for the week ending March 28, a sharp decline from the near-68% boost from the deluge of panic buying that occurred the week prior. 

There may be a new brief spike of panic buying as consumers squeeze in one last shopping trip before hunkering down. Officials say the next week or two could be the worst. They also encouraged shoppers to stay home.

"This is the moment to not be going to the grocery store, not going to the pharmacy, but doing everything you can to keep your family and your friends safe," Debora Birx, Coronavirus Response Coordinator for the White House Coronavirus Task Force, said.