If a broker trades against you, it means that two different customers receive two different prices. Have anybody of you noticed this broker's behavior? If yes, what is the difference (in price between customers of the some broker) and haw often this situation occur?
It depends both on your broker's minimum margin and on the contract price. At current price levels and using IB's Initial Intraday futures margins, leverage for each of the 6 majors is (rounded to the nearest integer):