You don’t state if it a Business or Private Balance Sheet
The solution would be to hold them as Inventory Items especially if they are bought & sold regularly.
This enables any disposal be transferred to the P&L without requiring separate Journals.
If there are other types inventory on the balance sheet, then you can set up the investments within there own inventory Custom Control Account.
Each purchase can be recorded as a separate inventory item, rather then an accumulation.
If you purchase 2000 shares on three separate occasions (without selling) then that becomes 3 inventory item rather then one 6000 inventory item which assists with later re-selling.
Brokerage can be added to the purchase and recorded when sold. Because of the custom income and expense feature, you can show any profit on sale or loss on sale on there own single P&L line
With regards to periodic re-valuations you set up appropriate accounts to receive this data
With regards to Dividends, these can be stored within their own P&L section.