This article explains the interest rate policy and funding fee mechanism in futures trading, covering both Cross Margin Mode and Isolated Margin Mode.
🔍 Interest Rate Policy
Currently, in bitcastle futures trading:
✅ Cross Margin Mode: Interest rate = 0%
✅ Isolated Margin Mode: Interest rate = 0%
bitcastle does not currently charge or apply collateral interest on margin balances.
However, traders should be aware that funding fees play an important role in futures trading.
💰 What Is the Funding Fee?
Funding fees are periodic payments exchanged between traders holding long and short positions in perpetual futures contracts.
Funding fees help keep the futures price close to the spot market price.
📊 How Funding Fees Work
• If the futures price is higher than the spot price →
👉 Long position holders pay funding fees to short position holders
• If the spot price is higher than the futures price →
👉 Short position holders pay funding fees to long position holders
🔍 Cross Margin Mode Characteristics
In Cross Margin Mode:
✅ Margin is shared across all positions
✅ Funding fees affect the overall margin balance
✅ Losses or funding payments may impact all positions
⚠️ Because margin is shared, funding fee costs may impact overall account risk.
🔍 Isolated Margin Mode Characteristics
In Isolated Margin Mode:
✅ Margin is isolated per position
✅ Funding fees are applied only to the specific position
✅ Risk is limited to the allocated margin for that position
💡 This allows more precise risk control per trade.
⚠️ Important Notes
🚨 Funding fees may reduce profits or increase losses
🚨 Funding fee rates may change depending on market conditions
🚨 Even though interest rates are currently 0%, system specifications may change in the future
🛡 Tips for Traders
Please monitor:
✅ Funding fee rates
✅ Margin balance
✅ Unrealized PnL
✅ Liquidation price
If you have further inquiries, please don't hesitate to contact our Support Team via "Contact Us" function.