"What the heck is a Margin Call?
In the event that money in your account falls below margin requirements (usable margin), your broker will close some or all open positions. This prevents your account from falling into a negative balance, even in a highly volatile, fast moving market.
Example #1
Let’s say you open a regular Forex account with $2,000 (not a smart idea). You open 1 lot of the EUR/USD, with a margin requirement of $1000. Usable Margin is the money available to open new positions or sustain trading losses. Since you started with $2,000, your usable margin is $2,000. But when you opened 1 lot, which requires a margin requirement of $1,000, your usable margin is now $1,000.
If your losses exceed your usable margin of $1,000 you will get a margin call.
Example #2
Let’s say you open a regular Forex account with $10,000. You open 1 lot of the EUR/USD, with a margin requirement is $1000. Remember, usable margin is the money you have available to open new positions or sustain trading losses. So prior to opening 1 lot, you have a usable margin of $10,000. After you open the trade, you now have $9,000 usable margain and $1,000 of used margin.
If your losses exceed your usable margin of $9,000, you will get a margin call. "
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