California voters will decide Proposition 42, a constitutional amendment that bars new state taxes after January 1, 2026, on personal property including retirement accounts and savings while prohibiting retroactive taxes based on prior residency or conduct. The measure directly counters the competing billionaire wealth tax initiative on the same November 3 ballot, with conflicting provisions resolved by whichever receives more votes. Trader sentiment remains closely balanced because the proposition appeals to voters prioritizing retirement security and tax predictability, yet faces opposition from advocates of revenue measures for public services. No major campaign developments or polling shifts have emerged since the measure qualified in June, leaving the outcome sensitive to overall turnout, spending on the paired tax initiatives, and voter views on wealth taxation versus fiscal limits.