I’m just recently trying capitally, and as far as I can tell it doesn’t support adding expenses which adjust the cost basis. This is something we do in Australia.
E.g., if you own property, you can add some expenses and rather than be income deductible, they actually increase the cost basis of the investment. E.g., a $1,000 expenses on an investment made for $100,000 will increase the cost basis of that lot to $101,000.
Or in some cases there may be an increase in the cost for a managed investment (called AMIT Cost basis increase), in which case the expense is actually distributed among all per-existing lots proportionality. E.g., you bought 100 units in a fund on 01/01/2024, then another 100 units on 01/12/2024. The $100 AMIT cost basis increase is then distributed so that $50 goes to the first parcel (100 * 100/200) and $50 to the second parcel.
Same principle might apply to gold bullion, for example, if there are custody fees.
As far as I can tell, capitally doesn’t support this. When I had an expense, unless it’s a fee linked to a specific buy/sell, it simply increases expense and is assumed to be income deductible rather than a part of capital gains cost.