Why MacKenzie Bezos Only Got 25 Percent of Ex-Husband Jeff's Fortune in $137 Billion Divorce

MacKenzie Bezos is walking away with $36 billion from her high-profile divorce to Amazon founder and CEO Jeff Bezos, but that amount is just a small fraction of his fortune.

MacKenzie, 48, received 25 percent of her ex’s massive wealth when the two finalized their divorce agreement on Thursday, three months after announcing they were separating. For his part, Bezos, 55, remains the richest person in the world post-divorce with a net worth of about $110 billion, according to Forbes. Bezos’ net worth pre-split was estimated at $137 billion.

But why is MacKenzie only receiving a quarter of Bezos’ fortune? The answer lies in how they divided their assets.

The Amazon chief is retaining 75 percent of the former couple’s Amazon shares, which is about 12 percent of the company, while MacKenzie, a book author, is keeping roughly 4 percent, according to The New York Times.

MacKenzie revealed details of what assets they had divided, writing she had given Bezos all of her interest in The Washington Post and his space company Blue Origin.

“Grateful to have finished the process of dissolving my marriage with Jeff with support from each other and everyone who reached out to us in kindness, and looking forward to the next phase as co-parents and friends,” she tweeted.

She continued, “Happy to be giving him all of my interests in the Washington Post and Blue Origin, and 75% of our Amazon stock plus voting control of my shares to support his continues contributions with the teams of these incredible companies.”

“Excited about my own plans,” she added. “Grateful for the past as I look forward to what comes next.”

RELATED VIDEO: Jeff Bezos Now Dating News Anchor Lauren Sanchez —Who’s Also Getting Divorced: Sources

MacKenzie, a book author, is now one of the richest women in the world, according to The Washington Post. She follows behind the $54 billion fortune of L’Oréal heiress Francoise Bettencourt Meyers and the $44 billion wealth held by Alice Walton.

MacKenzie and Bezos announced their divorce in January through a joint statement after 25 years of marriage and four children together.

RELATED: Jeff Bezos’ Ex-Wife MacKenzie Is ‘Grateful’ as She Lands $36 Billion in Divorce from Amazon CEO

A source told PEOPLE in January, Bezos and MacKenzie “grew apart without even knowing it.”

Added the insider, “Jeff is so busy in many areas where he is communicating with all kinds of people and traveling. On the other hand, MacKenzie is low-key, writing fiction and working on other projects while raising their children.”