Would be great to be able to create a formula in an account that calculates a value based off another account(s). For example, I would create a new account to estimate my taxes on my retirement holdings by taking the value of the Account and multiplying it by tax rate (which could be hard coded into the formula or stored in a septate account). This could impact my NetWorth by reducing the expected tax liability. Would be extremely helpful in differentiating between Traditional and Roth IRAs. Could be many, additional uses for this functionality and be a great differentiator from other products out there.