What is Margin?
Margin can be thought of as a good faith deposit required to maintain open positions. This is not a fee or a transaction cost, it is simply a portion of your account equity set aside and allocated as a margin deposit. Keep in mind that trading on margin can both positively and negatively affect your trading experience as both profits and losses can be dramatically amplified. You can keep track of your Used and Usable margin in the Accounts Window of the Trading Station.