I am using QC for Windows, starting with a lot of data downloaded from my broker.
The only way I have found to edit or even observe category assignments in investment accounts is with the Find/Replace function.
This is horribly cumbersome as compared to looking at the assigned category in a transaction register and changing it there, as one does with a Banking account. Quicken support confirmed for me there is no way to show the category column in an investment account transaction register, but I did not get an answer for why that is, whether its working as intended or just missing functionality that for some reason is difficult to get into the software.
So, for example -
What workflow do you use to do something like find all unbalanced investment transactions with category "_RlzdGain" , locate a matching "buy" transaction for a "sold" transaction and make sure both sides of the transaction have category "_RlzdGain" so that the Taxable Income YTD window on the tax planning screen will show a useful number? I seem to have many unbalanced assignments in this category where only the "Sold" transaction has this category assignment and the sum in this category is a large +ve number that is meaningless, because the "buy" transactions don't have this category.
I'd like to make this category work correctly as opposed to just marking it not tax relevant, but it seems really onerous to get there.