Billionaires Oppose California's Prop. 40 Wealth Tax

Billionaires across the political spectrum are opposing Prop. 40, which would tax the wealth of California's richest residents.

Updated on Nov. 3, 2026 in Public Companies

Billionaires Oppose California's Prop. 40 Wealth Tax

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Should the wealthiest Americans pay a wealth tax?

Billionaires across the political spectrum have come out in opposition to Prop. 40, a California measure that would impose a wealth tax. Some billionaires, however, support elements of progressive changes to the tax code.

Why it matters

Opponents argue the tax will drive the ultrawealthy and entrepreneurs out of California, eroding the state's long-term income-tax base and competitiveness. The debate highlights a broader split among wealthy figures over how taxes on fortunes and capital gains should be structured.

The Tax Foundation's analysis of 2023 IRS data puts the maximum adjusted gross income of the bottom half of workers at $53,801. Corporate stock buybacks are currently taxed at 1%, a rate that one billionaire has said he would raise.

The players

Mark Cuban

Mark Cuban is a billionaire entrepreneur and investor known for owning the Dallas Mavericks and appearing on the television show Shark Tank.

Jeff Bezos

Jeff Bezos is the billionaire founder of Amazon who has become one of the world's wealthiest individuals.

Bill Ackman

Bill Ackman is a billionaire hedge fund manager at Pershing Square Capital Management who is known for his outspoken commentary on social media.

The details

Billionaires argue that Prop. 40 would cause the ultrawealthy and entrepreneurs to leave the state. Investor Mark Cuban, who has paid his employees partly in equity since 1983, has voiced skepticism of wealth taxes, saying they could stunt investment in startups and small businesses.

1983: Mark Cuban began paying employees partly in equity when he started his first company.
May: Jeff Bezos advocated eliminating federal income tax for the bottom half of workers in a CNBC interview.
Last December: Bill Ackman criticized wealth taxes on social media.

Market Landscape

Prop. 40 is a California ballot measure that would tax the wealth of the state's richest residents, and its opposition spans billionaires across the political spectrum. Arnold's proposal, which would count gains as realized when transferred as a gift or at death, offers an alternative approach that would match tax rates on long-term capital gains and ordinary income.

If enacted, Prop. 40 would apply to California residents with significant wealth, and its effects would depend on how gains are realized and taxed. Readers with investment portfolios in appreciating assets should watch how the measure treats stock buybacks and gains transferred at death.

The takeaway

The opposition to Prop. 40 shows that even wealthy figures disagree sharply about how much the tax system should reach into fortunes. Investors and business owners in California should weigh how any wealth tax could affect capital decisions and where they choose to live.