“A growing coalition of unions, progressive advocacy groups and Democratic officials has endorsed a slate of six revenue bills, including a so-called mark-to-market tax on billionaires, which would require them to pay capital-gains taxes each year as their assets appreciate, even if they don’t sell
As an example, a person who owned securities with a fair market value of $2 billion at the start of one year and $2.5 billion at the start of the next would be charged 8.82% in state income taxes on the $500 million difference, even if the securities weren’t sold”