California voters face a closely contested November 2026 ballot measure that would bar new state taxes on personal property such as retirement accounts and investment holdings while limiting retroactive taxation based on pre-enactment status or conduct. The proposition emerged as a direct counter to the competing 2026 Billionaire Tax Act, with both measures designed so that the higher-vote initiative prevails if approved; this linkage has driven balanced trader positioning. Recent developments include substantial early fundraising by business-backed opposition groups, federal legislation targeting retroactive state taxes on former residents, and ongoing legal debate over the constitutionality of residency-based retroactivity in wealth-tax proposals. Upcoming campaign developments, voter mobilization around property protections, and any shifts in polling on the paired wealth-tax initiative could alter the narrow balance ahead of election day.