When you complete your application for a trading account, you also receive details for your AUD wallet (A Macquarie Cash Management Account). Macquarie do their own verification, so this can take a bit longer to be finalised (1-2 days), but it doesn't require completion for you to fund your account or fund your US account via POLi.   

You can fund this account also immediately, but you will only be able to transfer these funds out to USD once Macquarie has given it the all clear The AUD wallet is required as it allows you to return your USD to AUD and then transfer to your local bank account.  If you want to take the longer funding option, you can fund your AUD Wallet via EFT and have funds ready for when your account is being established. You'll need to come back to Stake to transfer them into $USD for investing, which is all done on Stake.