Perpetual Futures are a special type of Futures contract that have no expiration date and have an autorolling feature every hour.
To see Inverse cryptocollateralised Fixed Maturity Contract specifications please visit the other page here.
Below is a detailed table of characteristics, followed by multiple examples to demonstrate the mechanics of the Contract:
Perpetual Contract Specifications

BitcoinDollar Futures 
EtherDollar Futures 
LitecoinDollar Futures 
BitcoinCashDollar Futures 
RippleDollar Futures 


Contract Symbol 
PI_BTCUSD* 
PI_ETHUSD 
PI_LTCUSD 
PI_BCHUSD 
PI_XRPUSD 


Instrument Type 
Inverse Perpetual Futures 


AutoRoll Period 
Every 1 Hour 

Ratesetting Calculation Window 
Rate for next period is calculated over current 1 hour period (e.g., rate for 1213 UTC period is calculated in window between 1112 UTC 

Funding Rate 
Between start and end of Ratesetting Period the Funding Rate is computed as the timeweighted average premium, and standardised to a perhour basis. Permissible range per 1 hours: [0.25%, +0.25%] (i.e., 80 basis point magnitude for 24hour realisation period) 

Payout Frequency 
Continuously based on Funding Rate set at the end of the prior Funding Period. Positions will immediately and continuously receive or send funding while open in the perpetual contracts. The funding accumulates as UPL and settles every four hours at end of Funding Period, or when user changes net open position (whichever occurs first). 

Funding Rate Multiplier 
n = 24 This is the coefficient used in the calculation of the funding rate. A value of 1/n means that, ceteris paribus, it will take n hours to realise the Average Premium. Example: if the Average Premium is 0.36% for the one hour period, then Funding Rate is equal to 0.015%, meaning that over the course of 24 hours, this 0.36% total will be realised. 

Funding Rate Calculation 
In a given 1hour Funding Period, Premium values calculated from minutely perpetual contract prices (240 observations) using an Impact Mid are recorded versus the Real Time Platform Ticker. The Impact Mid is the median of the average entry price marketselling 1000 contracts and marketbuying 1000 contracts. The Average Premium is calculated as the average of the mid 30 observations recorded from above 60 observations. Finally, this value is weighted by the Funding Rate Multiplier. If Average Premium > 0 then for the 1 hour period, those in Long positions will continuously pay out to Short positions, which pushes the price closer to Index. If Average Premium < 0 then for the 1 hour period, those in Short positions will continuously pay out to Long positions, which pushes the price closer to Index. 

Contract Size 
1 USD 
1 USD 
1 USD 
1 USD 
1 USD 


Trading Hours 
24 hours/day, 7 days/week, 365 days/year (excluding maintenance) 

Price Quotation 
US Dollars per 1 bitcoin 
US Dollars per 1 Ether 
US Dollars per 1 Litecoin 
US Dollars per 1 BitcoinCash 
US Dollars per 1 Ripple XRP 


Tick Size 
0.5 USD 
0.05 USD 
0.01 USD 
0.1 USD 
0.0001 USD 


P&L Settlement Method 
Cashsettled in BTC 
Cashsettled in ETH 
Cashsettled in LTC 
Cashsettled in BCH 
Cashsettled in XRP 


Fee Structure 
Crypto Facilities uses a makertaker fee structure with volume incentives. Fees are calculated as a percentage of the notional order value for a matched trade. See our Fee Schedule for more information. No fees are charged on autoroll or funding payouts  these occur strictly between counterparties. 

Contract Expiration 
The perpetual futures are nonexpiring, which means that positions in the contract are never “expired” or “matured”, however there is a settlement process every four hours that applies funding to anchor the spot value to the Index. See Last Trading for more information. 

Settlement time 
Every 1 Hour at the end of the hour The accumulated unrealised funding is settled and new rate set based on TWAP premium to index in prior rate period.. 

Last Trading 
This contract remains trading perpetually and would only expire in emergency situation if Crypto Facilities deems necessary to settle/expire contract. This would only occur in exigent circumstances if the Market Risk Committee deemed it necessary to facilitate a fair and orderly market. Noting that the settlement process, occurring every four hours, is autorolling. See AutoRoll Period for specific times. 

First Trading 
August 31, 2018 

Initial Margin 
Minimum 2% depending on most instruments. See Margin Schedule 

Maintenance Margin 
Half of IM 

Position Limits 
See Margin Schedule 

Mark Price

The Mark Price is calculated using Index Price plus the 30 seconds exponential moving average of the order book mid price minus the index price (future's basis). The premium for perpetual contracts is capped at 1%. Calculation: Index Price + EMA_30seconds(Impact Mid Price  Index Price) 

Note: in the extremely rare circumstance that the Index Price is unavailable for whatever reason, the above caps may not apply and the Mark Price will be equal to the Mid Price. 

Real Time Platform Ticker 
IN_XBTUSD 
IN_ETHUSD 
IN_LTCUSD 
IN_BCHUSD 
IN_XRPUSD 


Margin & Settlement Currency 
BTC 
ETH 
LTC 
BCH 
XRP 

Note on Funding Rate
The funding rate for a given perpetual contract is represented in two different ways:
 absolute rate: The amount of funding an account will receive by maintaining a 1 contract unit short position for 1 hour. This is more useful for account log purposes.
 relative rate: The absolute funding rate relative to the spot price at the time of funding rate calculation. This is an intermediate value in the calculation of the absolute funding rate, and is the number we display in the front end (as a %) as the 'funding rate'.
Examples
In order to get a complete understanding the rate dynamics of the Perpetual Contract, we present examples to demonstrate the key features:
Example Funding Rate 1: (24hour rate realisation length)
Assume time is 12 UTC and that price of BTC is $7,000 (via realtime index) and the Perpetual trades at $7,010 the whole time until 13 UTC. The average premium is computed as 0.1428% for the 1hour period ($10/$7,000). This leads to a funding rate of 0.1428 / 24 = 0.01785% per hour.
Now assume that you are in a short position of 100,000 Contracts. If you hold this position from 13 to 14 UTC and the premium in 1314 UTC period remains as 0.1428%, then you will earn interest of $17.85 for the onehour period ($100,000*0.0001785) in BTC terms, so $17.85/$7,000 = 0.00255 BTC.
Example Funding Rate 2: (Maximum rate)
Assume time is 12 UTC and that price of BTC is $7,000 and the Perpetual trades at $7,500 until 13 UTC. The average premium is computed as 7.142% for the 1hour period. This leads to a funding rate of 7.142 / 24 = 0.2975% per hour.
The maximum funding rate per hour in any given period is 0.25%. The minimum is 0.25%.
As a result, this 0.2975% hourly rate is floored to 0.25% per hour, so that the maximum 24hour realisation will not exceed 6%.
Note that there is no "dampening" of rates done in this model: if a fourhour computed rate is near 0, then it will stay pay out non0 value even if it is de minimis.
Example Funding Rate 3: (Absolute vs. relative rate)
Assume time is 12 UTC and that the realtime index price of BTCUSD is $7,000 and the relative rate set for the onehour period is 0.05% per hour.
Now assume the time is 13 UTC and the Perpetual trades at $8,000 and you enter a Short position of 125,000 contracts at this price.
You will immediately begin receiving funding at an absolute rate of 0.05%/$7,000 = 0.000007142% per hour per contract unit.
In your account log you will then see this rate applying in your unrealised PnL through continuous funding payout equal to:
0.00000007142 * 125,000 = 0.008928 BTC per hour
0.00000248 BTC per second
This will pay out continuously until 14 UTC where the relative funding rate will change based on the market activity between 1314 UTC.
Assume this new relative funding rate is now 0.03% and the realtime spot index is $7,900 for BTCUSD at 14 UTC.
In your 125,000 Contract short position at the end of the 1 hour period you will have 0.008928 BTC applied in your account log at 14 UTC.
From 14 UTC to 15 UTC a new absolute funding rate will begin applying of 0.03%/$7,900=0.000003797% per hour per contract unit.
Example Funding Rate 4: (Multiple period rate)
Assume time is 14 UTC and you enter a position long 200,000 Contracts on BTCUSD at $7,000. Assume that the funding rate for the onehour period (1314 UTC) is set as 0.04% per hour.
At 15 UTC, after you have held this position for one full hour, you will have earned $80 per hour (0.0004*$200,000). This is $80/$7,000 = 0.0114 BTC, which credits continuously throughout the one hour period you hold it.
However, during this period, the price was at a premium and so the new onehour rate set for 14  15 UTC is 0.04% per hour. After one hour of holding the position, you have paid 0.0114 BTC and you close at 16 UTC, two hours after opening the position.
Your funding for the two hours you held the position is thus 0.0114 BTC for the first period then 0.0114 BTC for the first period and your net flows are 0 for this.
Example Funding Rate 5: (Booking of unrealised funding)
Assume it's 12 UTC you are in a 250,000 Contract long position on BTCUSD with realtime index at $7,000 and the rate in the funding period is 0.05%. This earns you funding of:
0.0005 * 250,000 = $125
$125/$7,000=0.01785 BTC per hour
0.0002976 BTC per minute
0.00000496 BTC per second
0.00000000496 BTC per millisecond
This credits and debits every millisecond to every user with an open position. It credits first as unrealised profit and loss, but you have the funds available right away to use in further positions or transfer into your Cash account.
The funding is booked into your account log and realised when one of the following events occur:
1) You adjust your open position up or down by any amount
2) You hold until the end of the Funding Period, at which point it is booked (occurs at the end of every hour)
*XBTUSD is used for logs download and API only