USX is a USD stablecoin pegged to the U.S. dollar. Its peg ($1 representation) maintenance is based on overcollateralised backing and protected by whitelisting the range of users who have access to direct fixed-rate USX - collateral exchange in either direction (i.e., minting and burning).
USX generates yield when locked in a eUSX vault (although yet more strategies can be added at a later date). This yield is a share of the income generated by a specific Solstice-run delta-neutral strategy.
This yield becomes available immediately after entering the vault, with no additional actions required, and is accrued in the form of eUSX appreciation (therefore, it is manifestly distributed pro rata).