Funding rate
The funding rate is a small payment exchanged between longs and shorts on a perpetual futures contract, every few hours, that keeps the contract's price close to the spot price.
When the perpetual trades above spot, the rate is usually positive and longs pay shorts; when it trades below, it turns negative and shorts pay longs. On a 5,000 USDT position, a rate of 0.01% per interval is 0.50 USDT each time. The interval and the rate depend on the exchange and the market, so check your exchange’s current schedule.
Learn more: funding rate explained, what a perpetual future is and short selling explained.