Position Funding Fee indicates the amount of margin held by the system to pay for the next funding*. The "Position Funding Fee" can be found under the Positions tab, by clicking on “Margin(Leverage)”. If the amount you see is zero, it means that no funding fee is held by the system from you as the position you held might be receiving funding fee at the next funding timestamp.
The calculation of Position Funding Fee**
For long position: (Quantity/Bankruptcy Price) x Funding rate
For short position: (Quantity/Entry Price) x Funding rate
Example: The next funding rate is -0.3750% as shown under "Contract Details BTCUSD". (Negative funding rate means short position pays long position)
Trader A sells 10,000 BTCUSD contracts at an average entry price of 3,841.17 USD using 10x leverage.
Short position: (Quantity/Entry Price) x Funding rate
(10,000/3,841.17) x -0.3750% = - 0.00976266 BTC
Hence, trader A has 0.00976266 BTC held by the system as Position Funding Fee.
Trader B who is holding a long position will see that Position Funding Fee is zero, which indicates that no margin is held by the system for the payment of funding fee. This is because the next funding rate is -0.3750%, which means that he will be receiving funding at the next funding timestamp instead of paying.
*Note: By default, Position Funding Fee will be deducted from the Available Margin. In the event whereby there is insufficient Available Margin, the Position Funding Fee will be deducted from the position, which will affect the liquidation price.
**Note: The actual funding fee exchanged between the long position and short position is calculated according to Mark Price.