The proposed California "entrepreneur's tax" is not a one-time levy on billionaires. It's viewed as the first step toward an annual tax on paper wealth, with thresholds planned to drop to $25M. This would impact founders with illiquid equity post-Series B, forcing a mass exodus before an IPO.

Mark Cuban warns that a California wealth tax would compel him to make startups leave the state as a condition for investment. This isn't just a threat of founders leaving; it's a structural shift where venture capital actively drains talent and future tax revenue from jurisdictions with hostile policies.

Congressman Ro Khanna proposes a tax on the total net worth of individuals with over $100 million. Unlike an income or capital gains tax, this targets unrealized wealth, forcing the liquidation of assets like stocks to generate the cash needed to pay the tax.

Ben Horowitz warns against wealth taxes on unrealized gains by citing Norway's experience. The policy required founders to pay taxes on their private company's rising valuation with illiquid stock, leading to an exodus of entrepreneurs and effectively dismantling the local tech ecosystem.

Mark Cuban criticizes the proposed 5% wealth tax, arguing most founders' net worth is in illiquid private stock they can't sell. The state's proposed solution—providing loans against these shares, which are then paid back as tax—is a nonsensical and inefficient circular transaction.

The proposed wealth tax applies to illiquid assets. A founder of a highly-valued private AI startup could be deemed a 'billionaire' and face a massive tax bill on paper wealth, even if their company never exits or ultimately sells for a much lower price, creating a huge financial risk.

A major flaw in the unrealized gains tax is that it punishes all investors for the actions of a few. A more targeted and less destructive approach would be to tax the loans that wealthy individuals take out against their stock portfolios, targeting the actual cash they use without harming the underlying assets.

Mark Cuban highlights a fatal flaw in wealth taxes aimed at startup founders: they are "cash poor, stock rich." Their billions are on paper, tied to their company's valuation. A wealth tax would force them to liquidate stock or take on impossible loans, crippling high-growth companies before they mature.

A tax on unrealized gains is fundamentally flawed because it requires payment on potential, not actual, money. To pay the tax, investors must liquidate parts of their holdings, like company shares, which can destroy the asset's long-term value and disincentivize investment and company growth.