This feature would only be made available if Cross Collateral is set as ON/enabled. 

You can enable the Negative Balance feature directly within ActiveTrader:

1. Log into your account via a web browser
2. Click the account name dropdown on the navigation bar at the top left of the screen, then click on “Edit accounts”
3. Select the account for which you want to change the settings
4. Ensure that Cross Collateral is enabled, then use the toggle to enable “Negative Balance”
5. Click Save to apply the settings

Alternatively, you can enable the Negative balance feature by navigating to the Manage accounts section of your Account Settings page. 

1. Log into your account via a web browser
2. Click the “Account” button on the navigation bar at the top of the screen and then “Settings”
3. On the left panel, select “Manage accounts”
4. Click on the gear icon next to the account name for which you want to change the settings and ensure that Cross Collateral is enabled
5. Use the toggle to enable “Negative balance”
6. Click Save to apply the settings