Mark Cuban Pushes Back on California’s Proposed 5% Billionaire Wealth Tax

Mark Cuban has criticized California’s proposed one-time 5% tax on the wealth of residents worth more than $1 billion, arguing that the measure could create major liquidity problems for startup founders whose wealth is tied to private-company shares.
Cuban said he has no issue paying taxes, noting that he paid $288 million to the IRS in a single year. His objection is taxing wealth that may exist only on paper. He warned that founders could face large tax bills without enough cash to pay them and argued the proposal could push entrepreneurs out of California.
Rep. Ro Khanna has proposed a government loan program for founders who lack liquidity, secured against their shares. Cuban criticized the idea, arguing that California could ultimately become a shareholder in private companies if founders default.
The proposed Billionaire Tax Act would impose a one-time 5% tax on California residents with more than $1 billion in net worth as of January 1, 2026. Supporters estimate it could raise nearly $100 billion, while opponents warn that wealthy residents could leave the state and reduce future tax revenue.