After specifying the growth of the Investment's underlying unit value (e.g., the share price of a stock), you must then specify your Initial Holding in the Investment, as well as any Purchases and Sales.
The "Purchases and Sales" portion of the Investment dialog is used to specify this information:
Note that these inputs are entered in terms of the value (in currency), as opposed to the number of units (e.g., number of shares). These inputs must all have the same order as the output (specified via the Type button). By default, they are scalar, but they can also be specified as vectors (e.g., to simulate a portfolio of investments).
The Initial Holding has units of currency and represents the value of the Investment at the beginning of the simulation. This must be greater than or equal to zero.
Purchases and sales can be specified as continuous rates and/or as discrete changes.
The Purchase Rate and Sales Rate fields accept constants or links (with dimensions of currency per unit time). These are treated as continuous rates. Hence it would be most appropriate to use these fields only if you had purchases and/or sales that could be approximated as being continuous (e.g., a daily purchase or sale). Purchase Rate and Sales Rate must be non-negative.
The Purchases and Sales fields accept discrete change signals. These fields are used to simulate transactions that must be treated in a discrete (as opposed to continuous) manner. The discrete change signals must have dimensions of currency.
Discrete change signals can be positive or negative. A negative Purchase is treated as a Sale, and a negative Sale is treated as a Purchase.
Sales only accept discrete change signals with Add instructions. Purchases accept discrete change signals with Add instructions or Replace instructions. When an Investment element receives a Discrete Change with a Replace instruction, the Investment value is reset to the Value specified by the Discrete Change.
The buttons to the right of the Purchases and Sales fields are used to enter multiple discrete changes. These buttons provide access to the following dialog:
Note that you can also enter multiple discrete change signals into this field by separating them by semi-colons:
Note:
If an Investment is inside an inactive conditional Container, all discrete and
continuous purchases and sales are ignored. If the purchases or sales
originate from an active Container, a warning message is written to the run
log.
Note Regular reinvestment of
dividends would be simulated by adding these reinvestments as discrete
purchases.
Learn more about: