Jeff Bezos is dethroned as the world's second-richest man as Oracle stock surges, making Larry Ellison the new number two.

• Since 2016, Jeff Bezos has been unseated as the second-richest person in the world by Oracle chairman Larry Ellison, who now has a net worth of $209 billion.
• In September, Oracle's shares experienced a 23% increase, setting them on course for their strongest month since October 2022.
• The AI boom has contributed to Oracle's stock success.

On Monday, shares surged more than 6%, pushing chairman Larry Ellison to become the world's second-richest person and taking the title from founder Jeff Bezos.

Ellison's net worth has increased by $11.7 billion since the close of trading Friday, reaching $209 billion, while Bezos' worth has decreased by $1 billion, leaving him worth $202 billion. Musk remains the wealthiest person on the list, with a net worth of $251 billion.

After reporting earnings that exceeded expectations and increasing its fiscal 2026 revenue forecast, Oracle's stock reached new heights, causing Ellison to briefly surpass Bezos as the world's second-richest person on Friday. However, Amazon founder reclaimed the title later that day.

Oracle's stock has experienced a 23% increase in value this month, which could make it their best month since October 2022, when they gained 28%, and their second-best month in nearly two decades, since October 2002.

Oracle's stock success can be attributed to its role in the artificial intelligence boom, as Ellison, the company's founder, discussed on the earnings call last week how Oracle is constructing data centers to meet the growing demand for generative AI.

Ellison stated on the call that we are constructing the tiniest, most portable, and most cost-effective cloud data centers, ranging from 200-megawatt data centers, which are ideal for training massive language models and keeping them current.

Oracle announced last week that it would collaborate with Amazon's cloud computing division to provide its database services on specialized hardware. In the past year, the company has also formed partnerships with Microsoft and Google, the other two major cloud infrastructure providers.

— CNBC's Jordan Novet and Ari Levy contributed to this report.