Free margin is the amount of your trade balance that is available for opening new positions.
Free margin is calculated as equity minus used margin.
For example,
- With equity of 8,750 USD, and
- used margin of 2,500 USD,
- free margin would be 8,750 - 2,500 = 6,250 USD.
If you try to open a position for which you do not have sufficient free margin, the order will be automatically cancelled (with the message "Insufficient initial margin").