Any negative balance must be cleared. This applies to any currency account. You can convert currencies yourself via the Accounts menu. Currencies are not automatically converted. You can make the necessary cash transfer or place a sell order for at least the same amount. Negative amounts on value date are subject to debit interests which are settled after each quarter.

In case of a negative balance, it is no longer possible to use the trading margin (30% of your portfolio value which is added to your amount available for trading). You will receive a notice of a negative balance on your cash account after five days. If your debit balance remains or increases, a registered letter will follow which may result in the automatic sale of (part of) your portfolio.