We report elsewhere in this issue on Senate Finance Committee Chair Ron Wyden's (D-Ore.) proposed mark-to-market tax on billionaires. On August 5, 2021, Wyden also introduced the Modernization of Derivatives Tax Act of 2021 (MODA). If enacted, MODA would impose mark-to-market treatment on all derivatives, tax gains and losses at ordinary rates, and source gains and losses based on the payee's residence. Regardless whether either proposal is enacted in its current form, the attention they have garnered suggests that more mark-to-market proposals are likely to be in our future.