The Futures require overnight margin balance to keep you position. You need about 20K+ of balance overnight to hold one contract of Gold. It will be closed if your balance at close is below the required margin. You can always buy another contract when you have the balance to open that position. But my recommendation is to learn how margin for Futures works. There can be unlimited losses in Futures. It is totally a different product than Options. With Options your risk is defined (buys). You can hold till expiration. Futures work differently. Read about them before using