What business leaders are saying — and doing — about California's proposed billionaire tax

Jensen Huang, Mark Cuban, and Sergey Brin have all commented on California's wealth tax proposal.

Tomohiro Ohsumi/Getty Images; Peter Joneleit/Icon Sportswire via Getty Images; Phillip Faraone/VF25/Getty Images for Vanity Fair Wealthy business leaders have come out for and against the California wealth tax proposal .

State labor groups proposed a 5% tax on California residents with assets exceeding $1 billion.

Mark Cuban said that only "idiot startup founders" will stay in California if it passes.

Some of the biggest names in business are speaking up about California's billionaire tax proposal.

Others are physically relocating.

The measure proposes a one-time 5% tax on California residents with assets exceeding $1 billion.

The measure was certified for the November 2026 ballot on June 25 after receiving enough valid signatures.

If the proposal passes, the tax would apply retroactively to all California residents as of January 1.

Proposed by the Service Employees International Union-United Healthcare Workers West labor union, the bill attempts to fill a projected multibillion-dollar state budget deficit.

California is home to some of the biggest companies — in both value and prestige — in the US.

The state boasts Hollywood and Silicon Valley, although some of the industries' key players have relocated .

In a letter to Gov.

Gavin Newsom obtained by Business Insider, attorney Alex Spiro wrote that his clients would "permanently relocate" if the tax becomes law.