US and Toronto Stock Exchange shares of Shopify, which have doubled in value this year and briefly made the company the most valuable Canadian company in May, were up more than 5 percent in late-morning trading on Monday.

Online sales at retailers, from cosmetics makers to pizza chains, have boomed in the wake of the COVID-19 pandemic, which has forced customers to stay indoors.

Bentonville, Ark.-based Walmart said it expected to add 1,200 Shopify sellers to its marketplace this year and that the partnership was focused on adding small and medium-sized US businesses to its platform, Walmart.com.

Last month, Walmart reported a 74 percent surge in quarterly e-commerce sales and discontinued operations at e-commerce start-up Jet.com, which it had acquired for $3.3 billion in 2016.

Shopify said the merchants would be able to connect their accounts to their Walmart seller accounts, before they could list their products separately on Walmart’s Web site.

“Walmart is the third-biggest marketplace in the US behind Amazon and eBay, both of whom are already channel partners for Shopify, so this partnership is a natural next step and frankly, a long awaited one,” Eight Capital analyst Suthan Sukumar said.

Shopify has announced similar partnerships with Facebook and Pinterest in recent weeks.