A margin deposit refers to the funds held in security that is required as a protection against possible losses. Let us imagine a situation where a ‘short’ EUR forward position is initiated, on which a 5% margin is requested. The position is ‘long’ USD 100,000 and the forward rate is EUR-USD 1.1111. Measured in EUR, the initial margin requirement is EUR 4,500 = 100,000 x 0.9000 x 0.05. If the position shows losses, the margin deposit may need to be increased, depending on the severity of the loss.