BitMEX is a Peer-to-Peer Trading Platform that offers leveraged contracts that are bought and sold in cryptocurrencies. We currently have contracts margined in Bitcoin and Tether (USDT - ERC20)
You can purchase both Bitcoin and Tether on BitMEX at https://www.bitmex.com/buy-crypto via our Fiat Gateway partner, Banxa. You are not able to sell Bitcoin or Tether for a fiat currency via this method and will need to use a spot exchange or a broker.
Once you have purchased either currency, you can find them on the balance page in your account here: https://www.bitmex.com/app/wallet/xbt