Definition – What does Bull mean?
A bull is an individual trader who believes a particular currency is set to rise in value against other currencies.
ForexTerms explains Bull
A trader can easily become a bull when it comes to a currency they regularly trade. Many traders go from being a dollar bull (USD) to a yen bull to a euro bull depending on how the global market is doing. Being a bull just means that you think a currency is undervalued and ready to make a run.