@balinsky
Tiller easily tracks transactions in your connected investment accounts and there are multiple add-ins that track investment returns by account, just not be individual holding. Reason is- Tiller does not have any insight into the specific equity purchased/sold, # of shares, or cost basis. You could enter this information manually, but you would still need to develop a spreadsheet that uses this info.
@heather has alluded to adding the capability to import this data from the financial institutions, but I have not seen anything indicating when or this will ever be implemented. If this data was automatically imported, I am confident a solution would be generated pretty quickly to track returns by ticker, etc.