By Marina Peña
Publication Date: 2026-08-11 03:00:00
Google co-founder Sergey Brin, the world’s fourth-richest man, has now spent more than $100 million to fight the Billionaire Tax and avoid shelling out an estimated $13.3 billion.
Brin’s net worth is estimated to be around $267 billion. He recently donated another $20 million to Build a Better California, which is an organization that advocated against California’s proposed billionaire tax, according to a recent filing.
Sergey Brin, co-founder of Google, at a dinner at the White House in Washington D.C. on September, 2025. Bloomberg via Getty Images
Google headquarters in New York (pictured). (Christopher Sadowski) Christopher Sadowski
Prop 40, known as California’s billionaire tax, would impose a one-time 5% tax on the net worth of around 200 billionaires that live in the state.
The funding from the proposed tax would be expected to go to California’s healthcare programs.
Governor Gavin Newsom has come out saying he’s against the tax and instead in favor of a “national billionaires’…
