The investment stack is the ordering of all currently opened investments. The investment stack determines which investment graphs will be displayed and their order. When the number of displays is set to 1, the investment on the top of the investment stack will be displayed. When the number of displays is set to 4 or 9 the top left graph will display the top of the investment stack. The subsequent investments on the stack will be displayed first from left to right, and then top to bottom, just as the writing on a page.
The investment stack can be manipulated in a variety of ways. The arrow and page up/down keys allow quick manipulation (see Keyboard Shortcuts). The Investments menu allows you to see the order of the investments in the stack, as well as manipulate the stack with the Order..., Select..., Invert Stack, Revert Order, and Sort By commands. Choosing an investment's name from the Investments menu scrolls that investment to the top of the stack, and sets the number of displays to 1. When an investment is opened or created it is placed on top of the investment stack.
The investment stack also determines the default order in which investments are displayed in reports. Reports can be sorted by the investment stack or any displayed column in the report. When sorting reports by a displayed column you can optionally have the investment stack updated to match this sort order. See the "Update Investment Stack When Sorting Reports" option in the Report Preferences - General Dialog.