When you place an order on Delta Exchange, margin is blocked  this is called order margin. You must have enough balance in your account to cover this. If you're placing multiple orders, more margin will be required, but margin offsetting is available to improve capital efficiency.

Exception: Stop Orders

No margin is blocked when placing a stop order. You can place multiple stop orders without using extra margin. However, once a stop order is triggered, it becomes a regular order and at that point, margin must be available.

 Important:

If there's not enough balance in your account when the stop order is triggered, the order will be cancelled automatically. To avoid this, always keep a small balance free when using stop orders.