Gold, Silver and Money

Forex trading

Q: Is fxcm.com halal or haram. It is forex. 

This is what you do in forex, buy 1 usd dollar when it is equal 2 euro dollar and sell it when it is more than 2 or equal to 3 usd dollars.

For example: I bought when it was like this, 1 USD = 2 EURO. I will sell when it becomes 1 USD = 3 EURO or more than 2 EURO.

So is it halaal or haram? Can you tell me why is it halaal or haram, and also say at the end of your answer, this "It is halaal" or "it is haram" so I can understand clearly.