Bezos and Gates have been fighting for the top spot for a while; Bezos was briefly the richest man in the world in July, before his share prices dropped a few hours later.
Bezos topped $100 billion in net worth in November. Most of Bezos' wealth comes from his Amazon holdings, tying his net worth to market fluctuations. According to CNN, he owns 78.9 million shares of Amazon.
Companies Jeff Bezos Swipes Title as Richest Man in the World
Bezos also holds shares in the Washington Post and Blue Origin, a privately-owned space travel business he eventually intends to take willing tourists to space. The stock is up about 7% in 2018 after soaring 56% in 2017.
Gates' previous record of richest person ever was set in April 1999, when he passed the $100 billion mark during the internet stock bubble.
Bezos came under fire a year ago when The New York Times questioned his level of philanthropic giving.