BitMEX offers an Inverse Perpetual Contract on Bitcoin against USD. The XBTUSD Perpetual Contract allows traders to get exposure to the future value of the Bitcoin / USD (XBT/USD) exchange rate.

Perpetual Contracts

You can trade Bitcoin (XBT) on BitMEX through an innovative type of contract called a Perpetual Contract which is aimed at replicating the underlying spot market but with enhanced leverage. This product does not have an expiry date (subject to the Early Settlement) and is able to closely track the underlying reference Price Index through various mechanisms, the main of which is known as the Funding Rate.

To view the current rates and calculations to determine the current Funding, please see the Funding Calculations in the XBTUSD Contract Specifications and more generally in the Perpetual Contracts Guide.

The product suits traders who prefer to hold positions for a long time and do not want their positions to fluctuate in value due to large swings in basis.

How is the XBTUSD Perpetual Contract Quoted?

The XBTUSD contract’s underlying price is the XBT/USD exchange rate as recorded in the .BXBT Index. Both the underlying and the swap contract are quoted in USD. Margin and PNL are denominated in Bitcoin.

	Contract Calculations
Multiplier	1 USD
XBT Contract Value	Multiplier / XBTUSD Price
USD Contract Value	1 USD
PnL Calculation	# Contracts * Multiplier * (1/Entry Price - 1/Exit Price)

Traders who want to profit from an increase in the Bitcoin / USD price, will buy the XBTUSD contract. Conversely, if they believe the price will go down they will sell the contract.

Margin and Leverage

All margin is posted in Bitcoin, which means traders can go long or short this contract using only Bitcoin. The XBTUSD contract features a high leverage of up to 100x.

For example, to buy 100 Bitcoin worth of contracts, you will only require 1 Bitcoin of Initial Margin.

Price Index

The BitMEX .BXBT Index is currently used for the XBTUSD Perpetual Contract.

Please refer to the .BXBT Composite Index Breakdown for information on the constituents and their weights.

Marking and Settlement

As the XBTUSD contract is perpetual, there is no settlement (subject to the Early Settlement). Marking for Unrealised PNL and Liquidation purposes are done according to the Fair Price Marking system.

Note also: since this product is a perpetual contract, funding occurs every 8 hours. Please see the Funding Section in the Perpetual Contracts Guide for information, and for the current rates please see Funding Calculation in the XBTUSD Contract Specifications.

XBTUSD Perpetual Contract Example

A trader goes long 50,000 contracts of XBTUSD at a price of 10,000. A few days later the price of the contract increases to 11,000.

The trader’s profit will be: 50,000 * 1 * (1/10,000 - 1/11,000) = 0.4545 XBT

If the price had in fact dropped to 9,000, the trader’s loss would have been: 50,000 * 1 * (1/10,000 - 1/9,000) = -0.5556 XBT. The loss is greater because of the inverse and non-linear nature of the contract. Conversely, if the trader was short then the trader’s profit would be greater if the price moved down than the loss if it moved up.