California voters face a closely contested November 2026 decision on Proposition 42, which would amend the state constitution to bar new taxes on personal property ownership—including retirement accounts, investments, and other assets—while restricting retroactive levies tied to pre-enactment residency or conduct. The measure emerged as a direct counter to Proposition 40’s proposed billionaire wealth tax, which relies on a January 1, 2026 residency snapshot and could be undermined if both pass. Trader sentiment reflects balanced campaign dynamics, with support from high-net-worth backers emphasizing savings protections and opposition highlighting revenue needs amid state budget pressures. Upcoming developments such as signature validation outcomes, polling shifts on wealth taxation, and legal challenges to retroactivity could narrow or widen the current narrow margin.