Forex Correlation: Avoid Placing the Same Trade 3 Times

You buy EUR/USD, then GBP/USD, then AUD/USD. Three charts, three setups, three tickets on the platform. But if all three are really a bet that the US dollar will fall, you have placed the same trade three times. That is what forex correlation is about.

This article explains what currency correlation means, how to read a forex correlation table, and why some pairs move together while others move in opposite directions. Then it turns the idea into a simple rule for capping your risk, with numbers from the site's shared $2,400 account.

What forex correlation means

Forex correlation describes how two currency pairs move relative to each other over a period of time. It is a number called the correlation coefficient. It runs from −1 to +1, and each end and the middle tell you something different.

• +1 (perfect positive): when one pair rises, the other rises by a proportional amount, every time.
• 0 (no relationship): knowing what one pair did tells you nothing about the other.
• −1 (perfect negative): when one pair rises, the other falls, every time.

Real pairs almost never hit the extremes. You will see numbers such as +0.85, +0.3 or −0.7. The closer a number sits to either end, the more the two pairs behave like one position. The closer to zero, the more independent they are.

Correlation says nothing about cause. Two pairs can move together because they share a currency, because the same news drives both, or by coincidence over a short window. Understanding the reason matters more than the number, because the reason tells you when the link might break.

Why pairs move together

Every forex position is two bets in one. Buying EUR/USD means you are long the euro and short the US dollar. That is why the pairs on your screen are less independent than their names suggest.

A shared currency

The simplest link is a currency that appears in both pairs. EUR/USD, GBP/USD and AUD/USD all have the dollar as the quote currency (the second one in the pair). When the dollar weakens broadly, all three tend to rise together. When it strengthens, all three tend to fall.

A shared driver

Pairs without a common currency can still move together. AUD/USD and NZD/USD are close partners because Australia and New Zealand are neighbors with similar export-driven economies and similar sensitivity to global risk appetite. They tend to rise and fall together even though Australian and New Zealand dollars are different currencies.

Opposite legs

Negative correlation usually comes from the same currency sitting on opposite sides. EUR/USD has the dollar second. USD/CHF has the dollar first. A rising dollar pushes USD/CHF up and EUR/USD down, so the two have often shown a strongly negative relationship. The Swiss franc also tends to track the euro, which reinforces the link.

Reading a forex correlation table

A forex correlation table is a grid with the same pairs down the side and across the top. Each cell shows the coefficient for that combination. The diagonal is always +1, because a pair is perfectly correlated with itself. The table mirrors itself across the diagonal, so you only need to read one half.

The table below is not a table of live numbers. Real coefficients change every week. It shows the direction and strength you have usually seen in these forex correlation pairs, and why. Always check a current table before you rely on any of it.

Gold also belongs in this picture. XAU/USD is priced in dollars, so it often moves opposite to the dollar and can line up with EUR/USD or AUD/USD. The link has been unreliable in some years, so treat it as a tendency to check rather than a rule. The article on gold and the FOMC shows how the dollar and rates push the metal around.

How correlation multiplies your risk

Suppose you follow the one-percent rule from the article on how to size a position. You risk $24 per trade on a $2,400 account. You like three setups: long EUR/USD, long GBP/USD and long AUD/USD, each with a 40-pip stop.

The lot size calculator gives 0.06 lots on each pair for a $24 risk. A 40-pip stop at 0.06 lots costs $24 whichever of the three it is. Each trade on its own respects the rule.

If the dollar jumps on an unexpected data release, all three can reach their stops within minutes. You did not lose 1% three times by bad luck. You lost 3% on one idea, and you chose that size when you placed the second and third ticket.

A rough way to estimate combined risk

For equal-sized trades with a similar correlation between each pair, you can estimate the combined swing with one formula. It is a guide for typical moves, not a worst case. The worst case is always the sum of the stops.

With three trades at 1% each, the estimate is 1.73% if the pairs are unrelated, 2.45% at a correlation of 0.5, 2.79% at 0.8 and the full 3.00% at 1. The higher the correlation, the less diversification you really have.

The same logic applies to drawdown, the fall from an account's peak. A cluster that moves together turns a normal losing streak into a deeper dip than you planned. The article on drawdown explains how that gap widens.

Three ways to handle correlated pairs

You do not have to avoid correlated pairs. You only have to count them honestly. These are the three most common approaches.

1. Pick the best one. If three pairs show the same setup on the same idea, trade the cleanest chart and skip the rest. One position at 1% risk is the same exposure with lower costs.
2. Split the budget. If you want all three, give the cluster one risk budget. A 1% cluster budget on this account is $24 in total, or about 0.02 lots on each of the three pairs (roughly $8 each, $24 combined).
3. Use correlation on purpose. Buying EUR/USD and USD/CHF together is largely offsetting, because the dollar sits on opposite sides. That can cut your dollar exposure, but a hedge that nets to nothing still costs you the spread twice.

The same habit applies to yen trades. Long USD/JPY, long EUR/JPY and long GBP/JPY all lose when the yen jumps, as the yen carry trade article shows. The lesson on correlated exposure turns this into caps per currency and per theme.

Common mistakes with currency correlation

• Trusting an old table. A coefficient from a book or a screenshot can be years out of date. Check a current one for the window that matches your holding time.
• Treating negative correlation as a hedge. Two opposite pairs can still both lose if the pair you hold moves against you and the other one does not follow.
• Counting tickets instead of legs. Three trades on three pairs can be three long positions on one currency. Count the legs, not the charts.
• Ignoring the crisis effect. In a sharp risk-off move, many pairs that looked independent can move together for a day or two.
• Using correlation to predict direction. The number tells you how pairs have moved relative to each other. It does not say which way either will go next.

Frequently asked questions

What is forex correlation?

Forex correlation is a measure of how two currency pairs move relative to each other over a set period. It runs from −1 to +1. A positive number means they tend to move in the same direction, a negative number means opposite directions, and zero means no consistent link.

Which currency pairs are positively correlated?

EUR/USD and GBP/USD, and AUD/USD and NZD/USD, are the classic examples of pairs that often move together. Pairs that share a currency, such as USD/JPY and GBP/JPY, also tend to rise and fall in step. Check a current table, because the strength of these links changes.

How often does currency correlation change?

It can change from month to month. Interest rate shifts, shocks and changes in risk appetite all move it. The window you pick also matters: 20 days and 200 days often give different answers for the same two pairs.

Can I trade correlated pairs safely?

No trade is safe, but you can size correlated trades sensibly. Treat the group as one position, give it a single risk budget and keep the combined stop loss total inside the limit you set for any single idea. CFDs are leveraged products and can lose money quickly.

Is a negative correlation a hedge?

Only partly. Two pairs that usually move in opposite directions can offset each other, but the link is not exact and it can break. You also pay the spread on both trades, so the combination costs more than doing nothing.