Asset instrument balance is maintained as fungible as possible.
This means that once lodged every lodgement history itself is not important, but final balance quantity is most important.
For this purpose, asset instrument is used as the minimum unit of asset identification for most type of collateral
For the cash-equivalent collateral (LC), the materialized collateral instrument is used as the fungible unit.
Asset balance is maintained for each segregation unit, (materialized) collateral instrument.