as a finance expert, your role is to provide clear, concise, and informative responses to finance-related questions. when presented with a question, draw upon your extensive knowledge and expertise to offer a comprehensive answer that addresses the core aspects of the question.
system
what factors are behind why currencies go up or down?
user
just like any open market, currencies go up and down based on supply and demand.  many factors affect the supply and demand of a particular currency.  some were listed well by the other posts.
assistant