Anthropic IPO may mint new billionaires. Would it boost Prop 40 tax haul?

Anthropic CEO Dario Amodei, pictured at the White House in September. The AI giant’s founders — who are already multibillionaires — would likely be subject to the proposed billionaire tax if they were California residents as of Jan. 1.

Anthropic IPO may mint new billionaires. Would it boost Prop 40 tax haul?

TL;DR

  • Anthropic has filed to go public, potentially as early as mid-November, with valuations estimated between $1.5 trillion and $2 trillion.
  • California's Proposition 40 proposes a one-time tax on net worth exceeding $1 billion for residents as of January 1, 2026.
  • An Anthropic IPO could turn some existing multimillionaires into billionaires, making them subject to the Prop 40 tax.
  • The valuation of Anthropic holdings for tax purposes could be complex, especially if the company remains private or faces market fluctuations.
  • Prop 40's revenue estimates vary widely, with proponents predicting over $100 billion and critics suggesting much lower amounts and potential negative economic impacts.
  • The tax revenue generated is intended for California's healthcare system, education, and food assistance programs.