LUSID is a transaction-based system. It does not maintain a static record of your holdings in a portfolio but rather generates them on demand from the stored history of transactions, replayed in date order.
This process is controlled using transaction types. Every transaction in a portfolio must resolve to a transaction type that defines the precise economic impact; that is, the effect on your holding in the underlying instrument, and also potentially on holdings in other instruments in the portfolio (such as currency holdings).
For example, the built-in
Buy transaction type provided with LUSID is intended to signal a purchase of an instrument such as an equity or bond. When you generate a holdings report, for every transaction with a transaction type of
Buy, LUSID automatically:
- Increases your holding in the underlying instrument (ie. BP) by the number of units purchased in the transaction.
- Decreases your holding in the transaction currency (ie. GBP) by the total consideration.
Note: LUSID reports holdings differently on the trade date vs. the settlement date. A holding has a holding type that indicates its state.
By default, LUSID reports holdings at the instrument level; that is, one holding per instrument transacted in the portfolio, and one holding per currency. You can change this:
- Using sub-holding keys (SHKs). For example, you could divide your overall position in BP into two holdings representing different investment strategies.
- Using tax lots to segregate and expand instrument holdings into separate tax lots according to a particular accounting principle.
Alternatively, you can interact with holdings programmatically:
- Using appropriate API endpoints in the Transaction Portfolios collection.
- Using the equivalent methods in the LUSID SDKs.
- If you have a Luminesce license, using dedicated read and write providers.
Explanation: See the big picture
Reference: Understand concepts and implications
- What is a sub-holding key (SHK)?
- What are the holding types?
- What are tax lots, and how does LUSID support tax lot accounting?
How-to guides: Get something done