Funding fee is charged every 8 hours, 08:00 (UTC+8) ; 16:00 (UTC+8) ; 00：00 (UTC+8)When the funding rate is positive, the Long side (Buyer) will pay the Short side (Seller) ; when the funding rate is negative, the Short side will pay the Long side.

Perpetual Contract USDT-M: Position Value * Funding Rate (Position Value = Par Value * Contract Quantity * Mark Price)
COIN-M: Position Value * Funding Rate (Position Value = Par Value * Contract Quantity / Mark Price).

For example:
USDT-M
Example: Par Value: 100USD/Cont ; Funding Rate: 0.01% ; The Mark Price at 08:00 is 20,000 USDT.
A holds 1 long positions, and B holds 1 short positions
A Funding fee (deducted)= 1 * 100 * 20,000 * 0.01% = 200 USDT
B Funding fee (received)= 1 * 100 * 20,000 * 0.01% = 200 USDT

COIN-M
Example: Par Value:100 USD/Cont ; Funding Rate: 0.01% ; The Mark Price at 08:00 is 10,000 USD.
A holds 100 long positions, and B holds 50 short positions
Based on the above information, the fees are calculated as follows:
A Funding fee (deducted)= 100 * 100 / 10,000 * 0.01% = 0.0001 BTC
B Funding fee (received)= 50 * 100 / 10,000 * 0.01% = 0.00005 BTC