Polymarket now prices the chance that California voters approve Proposition 40, a Nov. 3 ballot measure imposing a one-time 5% tax on certain billionaire wealth, at 32%, up 1 percentage point over the past week and 4 points over the past month after the proposal qualified for the ballot. More than $3 million has been wagered on the Polygon-based prediction market. Separately, a UC Berkeley Institute of Governmental Studies poll co-sponsored by The Times found 48% of likely voters support the measure, 41% oppose it and 11% are undecided, leaving it below the 50% support level that poll director Mark DiCamillo said is usually more comfortable for ballot measures because undecided voters often break against them. Supporters, including the California Democratic Party, Sen. Bernie Sanders and the union behind the initiative, say the tax would help address healthcare impacts from federal cuts, while critics including Gov. Gavin Newsom warn it could drive wealthy residents and capital out of California.