Bitfinex funding fees and net returns
Bitfinex quotes funding rates before its lender fee. That makes the rate on the funding book useful for comparing offers, but not the amount you actually keep. This guide turns daily rates into net income and shows where utilization changes the result.
The fee lenders actually pay
Bitfinex charges lenders 15% of generated funding income on standard visible offers. It is a fee on interest earned, not on the balance you lend. If an offer earns $10 gross, the standard fee is $1.50 and you keep $8.50.
This is separate from trading fees. Margin funding supplies capital to borrowers; it does not open a margin trade with your principal. Rates can change, loans may end early, and idle time between fills also reduces realized income.
The exact calculation
Net funding income = balance × daily rate × funded days × 0.85. Bitfinex API rates are decimals per day: 0.0003 means 0.03% daily, not 3%.
For $10,000 funded at 0.03% per day for 30 days: gross income is $90. The 15% fee is $13.50, leaving $76.50 net. That assumes the full balance remains funded for every day and ignores compounding.
For a comparable annual figure, multiply the net daily rate by 365. A 0.03% gross daily rate becomes 0.0255% net daily, or 9.31% simple net APR. It is not a forecast: market rates and utilization move continuously.
Net rate examples after the 15% fee
Net simple APR from 0.020% gross per day
Net simple APR from 0.030% gross per day
Net simple APR from 0.050% gross per day
Hidden offers cost more
Bitfinex lists an 18% fee on income from hidden funding offers. The same $90 gross example would therefore leave $73.80, not $76.50. Hiding an offer can reduce visible book impact, but the extra fee needs to earn its way back.
For hidden offers, replace 0.85 in the formula with 0.82. Always verify the current fee schedule before relying on a calculation, because exchange terms can change.
What improves realized return
The fee is fixed, but the gap between a quoted rate and the return you realize is manageable:
- Track utilization. A 10% APR while funded only 70% of the time realizes roughly 7% before compounding and other effects.
- Price from current data. Offers far above reachable demand can earn nothing while they wait; immediately taking the lowest rate can leave yield behind.
- Measure net ledger income. Use completed funding credits and fees, not open-offer APR, to judge a strategy.
Bitfinex funding-fee FAQ
Does Bitfinex charge 15% of my lending balance?
No. The standard fee is 15% of the funding income generated. Your principal is not multiplied by 15%.
Is daily rate × 365 the return I will receive?
No. It is a simple annualized snapshot. Future rates, early loan returns, idle time, fees, and compounding change the realized result.
Where can I calculate a balance and utilization?
Use the free Bitfinex lending calculator to enter balance, daily rate, duration, utilization, and the funding fee.
Calculate the amount you keep
Model a balance, current daily rate, utilization, and Bitfinex fee without connecting an API key.