CNBC's Robert Frank explained a controversy over California's proposed billionaire wealth tax, which would impose a 5% tax on wealth over $1 billion and could appear on the November ballot. Some tech founders and investors argue that super-voting shares could be valued as nonpublic assets, leading to a far larger tax bill for founders such as Larry Page and Sergey Brin. The tax authors dispute that interpretation, and Frank said ballot qualification, polling, legal challenges, and possible wealthy-resident departures remain uncertain. No direct investment trade was recommended.