Amazon (AMZN.O) announced that it has entered a definitive agreement to acquire Whole Foods Market (WFM.O) for US$42 per share in an all-cash transaction with a total value of approximately US$13.7 billion.

“Millions of people love Whole Foods Market because they offer the best natural and organic foods, and they make it fun to eat healthy,” said Jeff Bezos, Amazon founder and CEO said in a release Friday. “Whole Foods Market has been satisfying, delighting and nourishing customers for nearly four decades – they’re doing an amazing job and we want that to continue.”

Whole Foods will continue operating under its current brand, John Mackey will remain as CEO and the company's headquarters will remain in Austin, Texas.

“This partnership presents an opportunity to maximize value for Whole Foods Market’s shareholders, while at the same time extending our mission and bringing the highest quality, experience, convenience and innovation to our customers,” Mackey, Whole Foods Market co-founder and CEO, said in a release Friday.

“To me, this does change everything. This is big,” said Mark Satov, Strategy Advisor at Satov Investments, told BNN in an interview Friday. “But I don’t think this is a move they would make if they didn’t have to make it.”

“My biggest prediction about this is that they are then going to buy a mid-market grocer,” he added. 

Shares in Amazon rose two per cent at the market open Friday, while shares of Whole Foods shares surged more than 27 per cent in morning trading after initially being halted ahead of the opening bells. Loblaw, Metro, Empire and Wal-Mart all fell at the open in wake of the news. 

The takeover is subject to approval by Whole Foods Market's shareholders and regulatory approvals.The parties expect to close the transaction during the second half of 2017.