The USD value of the sub-account in use is shown by the account menu. Click on the account menu to display other sub-accounts and their balances.
The total and available balances for the instrument displayed on the chart and the sub-account currently in use are shown next to the deposit button (to the left of the account menu).
The total balance is the amount available to withdraw plus any balance used as margin for open positions plus the PnL. The available balance is the amount available for withdrawal or new positions.
The total and available balances of all assets for a particular sub-account are also shown in the browser panel.