Currency pairs do not move in isolation. They share currencies - EUR/USD and EUR/GBP both contain the euro, so euro strength affects both pairs. They share the US dollar - USD/JPY and AUD/USD are both affected by dollar movements, in opposite directions. They share macroeconomic environments - AUD/USD and NZD/USD both represent commodity currencies against the dollar and tend to move together. These interconnections create correlations - measurable relationships between pair movements - that every trader must understand before managing multiple open positions simultaneously.
What Is Currency Correlation?
Currency correlation is the statistical relationship between the price movements of two currency pairs over a defined period. It is expressed as a correlation coefficient between -1.00 and +1.00. A coefficient of +1.00 means the two pairs move in perfect lockstep - when one rises, the other rises by the same percentage. A coefficient of -1.00 means they move in perfect opposition. A coefficient of 0 means no measurable relationship.
In practice, correlations are never perfectly +1.00 or -1.00 - they are approximations that vary over time as market conditions change. A correlation of +0.85 between EUR/USD and GBP/USD means that approximately 85% of the time, when EUR/USD moves in one direction, GBP/USD moves in the same direction. Correlations above +0.70 or below -0.70 are considered strong.
Positive and Negative Correlations
Positive correlations exist between pairs that share a currency or share a similar economic character. Negative correlations exist between pairs that move in opposite directions - typically because one contains USD as a quote currency and the other contains USD as a base currency.
STRONG POSITIVE CORRELATIONS: EUR/USD and GBP/USD: +0.85 to +0.92 Both are USD quote pairs with European currencies as base. Dollar moves affect both in the same direction. AUD/USD and NZD/USD: +0.85 to +0.93 Both commodity currencies against USD. Both sensitive to risk appetite. EUR/USD and AUD/USD: +0.70 to +0.80 Both are USD quote pairs - dollar direction affects both similarly. STRONG NEGATIVE CORRELATIONS: EUR/USD and USD/CHF: -0.85 to -0.95 Dollar is quote in EUR/USD, base in USD/CHF. Dollar strength pushes EUR/USD down and USD/CHF up. EUR/USD and USD/JPY: -0.50 to -0.75 (Variable - depends on risk sentiment. In risk-off, both can fall as JPY and CHF both strengthen.)
Key Correlations Every Trader Knows
Certain correlations are stable enough over time to serve as reliable general rules - though always verify current correlation data before relying on them.
EUR/USD + GBP/USD: Strongly positive. Both long = double USD short exposure. EUR/USD + USD/CHF: Strongly negative. One long + one long = dollar neutral. This is effectively a hedge. AUD/USD + NZD/USD: Strongly positive. Both long = double commodity currency, double risk-on exposure. USD/JPY + AUD/JPY: Positive in risk-on. Both benefit from JPY weakness. Less reliable in risk-off (JPY dynamics dominate). Gold (XAU/USD) + AUD/USD: Positive. Australia is a major gold producer. Gold price affects AUD fundamentals.
How Correlations Affect Risk
The most practical implication of correlation is its effect on your actual risk exposure. If you hold a long EUR/USD position and a long GBP/USD position simultaneously - with 2% of your account at risk on each - you do not have 2% risk on two independent trades. You have effectively 4% risk on a single bet: that the US dollar will weaken. Because the two pairs have a +0.90 correlation, both will be affected in the same direction by dollar movements - and both will hit their stops simultaneously if the dollar strengthens sharply.
Check the correlation between any two pairs before opening a second position. If the correlation is above +0.70, treat them as the same trade for risk calculation purposes. Your true risk on each is not 2% - your combined risk on the correlated direction is effectively 4%. Adjust position sizes to account for this.
Using the Correlation Tool
Our free Currency Correlation tool shows you the correlation coefficients between major pairs in a clean matrix format. Check it before opening any second position. The tool displays correlations colour-coded by strength - strong positive correlations in green, strong negative in purple, low correlation in muted tones.
Correlations change over time as market conditions shift. The EUR/USD and USD/JPY correlation, for example, can shift from moderately negative to nearly neutral during risk-off periods when both are influenced by safe haven flows. Check current correlation data weekly rather than relying on historical relationships as fixed rules.