On 23 September 2026, Zuckerberg's net worth surpassed Brin's, making him the world's fifth-richest person. Expectations for Meta's new AI agent, Muse, drove up the share price and significantly increased his total net worth.
On 23 September 2026, US time, Mark Zuckerberg's net worth surpassed that of Google co-founder Sergey Brin, making him the world's fifth-richest person. Zuckerberg's wealth increased by approximately $4 billion on the day alone, bringing his total net worth to approximately $256.8 billion.
By contrast, Brin's wealth had declined by approximately $9 billion as of that afternoon. Meta's share price was up approximately 2.1% as of 2:00 p.m. the same day, with the price per share exceeding $750. Brin is a controlling shareholder of Alphabet.
Muse was released as a personal AI agent for general consumers. It supported the rise in Meta's share price following its release on 8 September and surged approximately 11% on the 21st. The stock's gain over the past month exceeded 34%, which some believe also contributed to the increase in Zuckerberg's wealth.
JPMorgan analysts forecast that Muse could become "the most widely used consumer AI app since ChatGPT." Apptopia estimates that Muse recorded approximately 2.8 million downloads following its release.