Funding Fee

Funding Fee Formula

1. global funding fee APR

$$FundingFeeAPR_{before\_clamp} = \\abs(LongOI-ShortOI)^{FundingExponentFactor}*FundingConstantMultiplier\\/(LongOI +ShortOI + FundingConstantFactor * TotalVaultBalance) \\ Condition:(0<abs(LongOI-ShortOI)< MaxExposureLimit)$$

$$FundingFeeAPR = Clamp(FundingFeeAPR_{before\_clamp}, L, U)$$

1. APR on each side

$$abs(APR_{long\_position}) = FundingFeeAPR * max(LongOI, ShortOI) / LongOI \\ abs(APR_{short\_position}) = FundingFeeAPR * max(LongOI, ShortOI) / ShortOI$$

$$if \ LongOI > ShortOI:APR_{long\_position} >= 0,APR_{short\_position} <=0 \\ else :APR_{long\_position} <= 0,APR_{short\_position} >= 0$$

i.e. when LongOI > ShortOI, long positions needs to pay funding fee (APR ≥ 0), short positions receives funding fee (APR ≤ 0)

1. the final pending funding fee of an open position

$$funding\ fee = time\_weighted\_average\ APR_{longORshort\_position} * seconds\_elasped \ / seconds\_in\_a\_year \ * position\_size \ * relative\_price$$

note: time weighted average APR is the average APR value over the duration that this open position existed (since the last time that the funding fee was charged). Notice that the APR is basically a function of LongOI and ShortOI.

Funding Fee APR Clamp Range

Currency	Clamp / L APR	Clamp / U APR	FundingConstantMultiplier	FundingExponentFactor	FundingConstantFactor
Group 1: BTC, ETH	-150%	+150%	3	1	70%
Group 2: ADA, AVAX, BCH, DOT, EOS, ETC, FIL, LINK, LTC, TRX, XRP, ARB	-300%	+300%	5	1	20%
Group 3: Top(50)	-900%	+900%	10	1	10%