Yes. In the event where the aggregate profit/loss on derivatives exceeds the cash balance, Saxo will reimburse the negative cash amount once the trades settle.
The reimbursement is based on the aggregate profit/loss across all derivatives positions and the existing cash, so in particular if the unrealized gains across positions are 4000 and the unrealized losses are 7000, and the cash balance is 2000 prior to the trades settling, then following settlement the cash balance will be -1000. Saxo will reimburse this amount.
Saxo will not reimburse any negative amounts booked to the account that are not related to the derivative losses, e.g., any amount that appears in transactions not booked on the day (such as the cash amount used for buying shares), or service fees such as market data fees etc.