Overnight interest represents the interest that occurs when a market position is held overnight. Holding money earns you interest and borrowing money costs you interest. When you participate in forex trading, you are using currencies that accumulate/cost interest. The method for calculating this interest is: opening price × contract size × day / 360 × interest rate During the weekend there is a compulsory locking of open positions. This means that they system will automatically lock open market positions, freezing the buy/sell price at the time of the market close. The weekend starts on Friday GMT 21:00 and markets open back up Sunday GMT 20:00. In the instance of a holiday, open positions will also be locked.
Maintenance margin refers to the requirement to have a certain amount of margin in the customer's trading account to withstand market volatility during the time while the position is open. If the client account margin ratio falls to 30% or less, the system will be forced to stop the transaction at that time.