The location comes from the banknotes with the image of Yuan Shikai in the Republic of China. The bigger the position, the thicker the banknotes, which means that you have more money. The mortgage of futures positions is the size of the mortgaged assets in your futures investment. If there are stocks in the collateral, then the value of this asset is changing, and it may be that the collateral position is insufficient and it is forced to close the position.