The official governance page shows that the Frax Finance community has initiated a proposal to "introduce USTB as collateral and custody assets for frxUSD", proposing to introduce USTB, the Superstate's short-term U.S. government securities fund, as the reserve behind the stablecoin, providing stability, liquidity and treasury yields.
USTB is a tokenized (ERC-20) fund that provides investors with short-term U.S. Treasury exposure. USTB's investment objective is to seek current income consistent with liquidity and principal stability, with a goal of returns consistent with the federal funds rate.
The proposal aims to introduce USTB as a collateral asset with an initial cap of $100 million. Voting is currently open and will end on January 1 next year.