"Capital Gains are calculated based on the Cost Base expressed in AUD (at the purchase transaction date exchange rate) taken from the Sale Proceeds expressed in AUD (at the sale transaction date exchange rate).”
IB normally keep the sale proceeds in foreign currency, similarly to interest, I think the realized income should not include any USD asset even the dollar itself, coz it's still subject to forex rate change when you take it back to AUD, and it could means tax gain/loss.
