California’s Proposition 40, which would impose a one-time 5% wealth tax on residents with net worths exceeding $1 billion, has seen its prediction-market odds of passage rise from 28% a week ago to 31.5%. The measure is supported by the Service Employees International Union–United Healthcare Workers West but opposed by California Governor Gavin Newsom. Polling shows plurality support without a majority, leaving public opinion divided as the vote approaches. The proposal’s potential effects on California’s economy and affluent residents remain subjects of debate. Former President Donald Trump is separately advocating voluntary artificial intelligence regulations, contrasting with Proposition 40’s binding tax framework. With 34 days remaining, observers are watching new polls, endorsements that could affect Governor Newsom’s stance, and financial commitments from supporters or opponents for signs of changes in market expectations.