Funding Fee
Funding rates are periodic payments made to either long or short traders, calculated based on the difference between the perpetual contract prices and spot prices. When the market is bullish, the funding rate is positive and tends to rise over time. In these situations, traders who are long on a perpetual contract will pay a funding fee to traders on the opposing side. Conversely, the funding rate will be negative when the market is bearish, where traders who are short on a perpetual contract will pay a funding fee to long traders.
Funding rate is primarily used to force convergence of prices between the perpetual contract and the underlying asset.

How are Funding Rates calculated?

Funding Amount = Nominal Value of Positions × Funding Rate
Funding payments occur every 8 hours at 00:00 UTC; 08:00 UTC and 16:00 UTC for all Binance Futures perpetual contracts. Traders are only liable for funding payments in either direction if they have open positions at the pre-specified funding times.
For more details about the funding fee, please refer to Binance Official Announcement:
Introduction to Binance Futures Funding Rates | Binance