Amazon announced today it will acquire the Whole Foods Market for approximately $13.7 billion. The acquisition comes as the two companies agreed to enter a definitive merger agreement in which Amazon will acquire the supermarket chain for $42 per share in an all-cash transaction, and it will include Whole Foods' net debt.

“Millions of people love Whole Foods Market because they offer the best natural and organic foods, and they make it fun to eat healthy,” Amazon CEO Jeff Bezos wrote in a statement. “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 to operate under its brand name and cofounder John Mackey will remain CEO. Mackey stated that this merger will allow the company to "maximize value for Whole Foods Market’s shareholders" while also "bringing the highest quality, experience, convenience and innovation to our customers."

Amazon was rumored to be interested in buying Whole Foods last fall, but the company didn't go through with the deal at the time. Speculation about the sale of Whole Foods popped up again earlier this year when activist investor Jana Partners LLC acquired a stake in the company and urged it to either accelerate its turnaround or sell itself.

It's no secret that Amazon wants to be in the grocery business, but it has proven to be harder to break into than other industries. Currently Amazon's Fresh grocery delivery service is only available in 16 cities across the globe (only two of them are outside the US), and it doesn't seem that the company has convinced most people that groceries should be purchased online like other goods. Amazon recently opened up a few of its own "Fresh Pickup" grocery stores in Seattle where Prime customers can order groceries online and go pick up their orders themselves, eliminating the shipping and handling costs of getting groceries delivered to your home.

Since Whole Foods will presumably operate as normal for now, it's unclear how Amazon will use the organic grocery store chain in practice. The most obvious perk is that Amazon will have over 450 brick-and-mortar stores across the US once the deal closes. Whole Foods also already has its own grocery delivery service, but it's not available everywhere that its physical stores are located. However, Amazon could use the local Whole Foods stores across the country to quickly expand its Fresh delivery service.

The news of Amazon's purchase is already sending ripples through the supermarket industry: Kroger stock fell 11.8 percent, Supervalu fell 4.3 percent, and Costco dropped 2.7 percent this morning. The deal is expected to close in the second half of 2017.