Perpetual futures are futures with no expiration or settlement date. They're USDT-margined.

Funding fee mechanism: Funding fees are settled periodically. The default settlement cycle is every 8 hours (00:00, 08:00, 16:00 UTC+8), though some contracts settle every 1, 2, or 4 hours instead. At each settlement, funding fees are exchanged between long and short position holders based on open positions at that point in time, calculated using the current funding rate.

・If the funding rate is positive, long position holders pay the funding fee to short position holders.

・If the funding rate is negative, short position holders pay the funding fee to long position holders.

・Funding fee is calculated as follows:

・To learn more about the funding rate, Learn more.

Delivery futures are USDT-margined.

・Delivery futures typically expire quarterly or bi-quarterly, though delivery cycles may vary by underlying.

・Settlement price is based on the average index price in the 30 minutes before expiry. Settlement time is 08:00 UTC+0. Buyers and sellers settle PnL in USDT.

Index price is calculated from a weighted average of quotes from multiple exchanges. Weights are adjusted based on factors like data availability and volume from each exchange.

Learn more about index price calculation, Learn more.

The exchange uses the mark price to estimate a futures contract's effective value.

The primary use of mark price in trading is to calculate floating PnL. Liquidation will be triggered if the account's MMR (calculated using the mark price) reaches the liquidation threshold.

・Mark price = median(Price 1, Price 2, Last price)

・Price 1 = Index price × [1 + Last funding rate × (Time until next funding/Funding interval)]

・Price 2 = Index price + 5-minute moving average

・5-minute moving average = Moving average of [(Bid + Ask) / 2 − Index price], sampled every 5 seconds over a 5-minute interval.

・When time to delivery > 30 minutes: Mark price = Index price × (1 + Basis rate)

・When time to delivery ≤ 30 minutes: Mark price = Index price averaged over the past 30 minutes (weighted by second)