Bitmex Contracts. What is XBT / USD
The Bitcoin XBT ticker denotes Bitcoin, this short name is assigned based on the uncertainty of the country of origin. By analogy with gold (XAG) or silver (XAU).
On Bitmex, Bitcoin, having the XBT ticker paired with the USD dollar, acts as a contract. A swap is a perpetual contract (unlimited time). Here you will have to come to terms with the fact that this is a common analogue of the usual BTC / USD pair on a traditional exchange. Thus, the trading pair against the dollar on Bitmex will be called XBT/USD. Contracts with other currencies have the usual names Cardano (ADA), Bitcoin Cash (BCH), EOS, Ethereum (ETH), Litecoin (LTC), Ripple (XRP).
The most liquid (with large volumes) instrument is a perpetual XBT / USD contract, therefore we recommend using it in trading.
We do not recommend trading futures contracts; futures have an expiration date. During the expiration, all positions will be forcibly closed.
The liquidity is less than perpetual contracts.
Can bargain with a premium. If there are more longists, then the price will be higher than swap. If everyone is short, the price is lower. This can be used to your advantage.