Dinard888 posted: Could someone explain me why a pair can decrease or increase margin? how is it calculated ?
It is very easy. If you are buying some currency e.g. EUR you need to pay the cost in other side of pair. So when you buy 1 lot EURUSD you are buying 100 000 EUR for 118 000 USD. Clear? So without any leverage margin requirement to open the position would be 118 000 USD. Not including the spread, comissions, price movement etc... With leverage lets say 1:100 you need just 118 000/100 = 1,180 USD to open such position. I had some topic here where I tried to explain why low leverage is dangerous. You can read more about it https://www.myfxbook.com/community/experienced-traders/low-leverage-is-dangerous-why/1194634,1