Step 1: Calculate Premium Rate = (Mark Price - Bit.com Index) / Bit.com Index * 100%
Step 2: Calculate Funding Rate = Max (0.05%, Premium Rate) + Min (-0.05%, Premium Rate)
Step 3: Calculate Time Fraction= Funding Rate Time Period / 8 hours
Step 4: Calculate Funding Payment
Funding Payment = Funding Rate * Position Size BTC * Time Fraction