By default, LUSID separates holdings at the instrument level, i.e. two transactions in the same instrument will contribute to the same holding. This also applies to cash, where separate holdings (balances) are created for each currency.
There are various instances where it is desirable to separate the holdings further:
- You want to account for different types of cash balances, e.g. principal, income, margin
- You want to segregate holdings in a single instrument based on a strategy tag supplied with the transaction, allowing the performance of individual strategies to be calculated - see how are Subholding keys used to capture different investment strategies?
The sub-holding keys that LUSID will use to generate the holdings are configurable when the portfolio is created. Note: Since they play such a critical part in how holdings are calculated by LUSID, it is not possible to update a portfolio's sub-holding keys after it has been created.
The values for these sub-holding keys are then provided at a transaction or holding level when these are loaded into LUSID.