The inventory fee is overnight interest. Overnight fee refers to the fact that after placing an order on the trading day, investors do not close their positions on the same day, but hold positions overnight until the second trading day, so there will be an overnight fee for holding positions in this process. Strictly speaking, it is the funds generated by investors' delayed delivery.

The calculation formula of overnight fee for gold speculation is: opening price × contract unit × lots × interest rate 1.25%×( 1/360). Take the gold trading platform in China, Jin Rong as an example. The overnight rate where investors buy positions is 2.0%, and the overnight rate where investors sell positions is 1.0%.