What are the Key Fundamentals for Currencies? Corvin Codirla, ex-hedge fund manager and trader comments. What influences move the markets. One of the most important is interest rates. When it comes to currencies it is all about interest rates. Currencies is cash and what do you tradtionally with cash; you stick it into the bank and it earns interest. If you live in a country with low interest rates and you know of another country with much better rates then you have a desire to invest in that country. So you need to have a good grasp of fundamentals to trade the forex markets?