US equities finished flat on Friday, as gains in primary industry outweighed a sharp drop consumer staples after Amazon announced it had agreed to buy Whole Food.
The high-end American grocer is planning to operate its network of stores under the same brand, and maintain its current executive team.
The deal is expected to close in the second half of 2017.
WalMart bought Jet, an ecommerce site trying to compete with Amazon, for $3.3 billion in 2016.
Whole Foods' stock was halted.
Moody's lead retail analyst Charlie O'Shea said the deal could be "transformative, not just for food retail, but for retail in general".
"Whole Foods Market has been satisfying, delighting and nourishing customers for almost four decades - they're doing an awesome job and we want that to continue", Bezos said in a statement.
Whole Foods came under pressure earlier this year to find a buyer after activist investor Jana Partners acquired a stake of more than 8 percent and began pushing for a buyout.
Following the announcement, shares of the e-commerce giant headquartered in Seattle, Washington state, rallied 3 percent while shares of Whole Foods spiked over 27 percent. Whole Foods co-founder John Mackey will remain Whole Foods' chief executive. In the all-cash deal, Amazon is set to take over the Texas-based chain for a $42 share.
Amazon's online prowess online, its ruthless focus on efficiency and its fierce ambition could mean lower prices at Whole Foods, along with an aggressive meld of internet sales. The shopper's Amazon account gets automatically charged. Kroger, which plunged 19 percent a day ago, lost another $2.27, or 9.2 percent, and hit a three-year low of $22.29. Whole Foods will keep operating stores under its name. The supermarket sector got even more crowded on Thursday, when Germany-based discount chain Lidl opened its first 10 US stores. Whole Foods last month unveiled a sweeping overhaul of its board, replacing five directors, naming a new chairwoman and bringing in a new chief financial officer. "We believe it presents an incredible opportunity to take Whole Foods Market's mission and goal to new levels and will create significant value for our stakeholders - including you, our most loyal customers".
Whole Foods, often derided as "Whole Paycheck" for its high prices, could see its reputation change if Amazon, a master at undercutting its brick-and-mortar rivals, passes any savings from automation to customers. The company might be able to sell cheap groceries as it makes its money from its cloud computing business and its very big online marketplace.
"Food is the one thing Amazon hasn't been able to figure out", said Josh Olson, a technology analyst at Edward Jones.
"The guidance was below what most were anticipating", said Vali.