Proposition 42, a November 2026 California constitutional amendment, seeks to bar new state taxes on personal property ownership such as retirement accounts and investments while restricting certain retroactive levies tied to pre-enactment residency or conduct. Trader sentiment remains closely balanced around the 52% "No" threshold because the measure directly counters the proposed Proposition 40 wealth tax on billionaires, splitting support along partisan lines with strong Democratic backing for revenue measures offset by Republican and business opposition to expanded taxation and retroactivity concerns. Key factors include competing ballot measures that could nullify each other based on vote totals, ongoing legal questions around due process and residency rules, and mixed polling trends on related tax initiatives. Developments such as shifts in campaign spending, endorsements from major groups, or updated voter surveys on fiscal policy could alter the narrow margin before election day.