In order to trade using the Bitcoin currency, you would need to create a BTC Live MetaTrader account.
To do so, you will need to select the BTC option when creating your account.
Upon doing so, your balance will be displayed in BITs in your Meta Trader account.
BIT is the sub-unit of 1 Bitcoin (BTC).
As an estimate, 1 BIT is equal to 1cent of $1.