Currency correlation refers to how well one currency correlates with other currencies.
Currencies will high correlation will react to the changes in the Forex Market in the same way.
Currencies with low correlation will react in opposite was to changes in the Forex Market.
Metaf.net provides really good currency correlation information. Use this link or click on the picture below: https://www.mataf.net/en/tools/01-01-correlation
Using Currency Correlations To Your Advantage
To be an effective trader, understanding your entire portfolio’s sensitivity to market volatility is important. This is particularly so when trading forex. Because currencies are priced in pairs, no single pair trades completely independent of the others. Once you are aware of these correlations and how they change, you can use them control your overall portfolio’s exposure. (For a guide to all things forex, check out our Investopedia Special Feature: Forex.)
The reason for the interdependence of currency pairs is easy to see: if you were trading the British pound against the Japanese yen (GBP/JPY pair), for example, you are actually trading a derivative of the GBP/USD and USD/JPY pairs; therefore, GBP/JPY must be somewhat correlated to one if not both of these other currency pairs. However, the interdependence among currencies stems from more than the simple fact that they are in pairs. While some currency pairs will move in tandem, other currency pairs may move in opposite directions, which is in essence the result of more complex forces.
Correlation, in the financial world, is the statistical measure of the relationship between two securities. The correlation coefficient ranges between -1 and +1. A correlation of +1 implies that the two currency pairs will move in the same direction 100% of the time. A correlation of -1 implies the two currency pairs will move in the opposite direction 100% of the time. A correlation of zero implies that the relationship between the currency pairs is completely random.
Reading The Correlation Table
With this knowledge of correlations in mind, let’s look at the following tables, each showing correlations between the major currency pairs during the month of February 2010.
The upper table above shows that over the month of February (one month) EUR/USD and GBP/USD had a very strong positive correlation of 0.95. This implies that when the EUR/USD rallies, the GBP/USD has also rallied 95% of the time. Over the past 6 months though, the correlation was weaker (0.66) but in the long run (1 year) the two currency pairs still have a strong correlation.
By contrast, the EUR/USD and USD/CHF had a near-perfect negative correlation of -1.00. This implies that 100% of the time, when the EUR/USD rallied, USD/CHF sold off. This relationship even holds true over longer periods as the correlation figures remain relatively stable.
For more information about currency correlation use this link:- http://www.investopedia.com/articles/forex/05/051905.asp