Why currency pairs move together
Two correlated pairs are usually one position taken twice. Long EUR/USD and long GBP/USD is not two ideas about Europe, it is one bet against the dollar at double the size. Seeing that before you place the second trade is worth more than any correlation table.
All 28 pairs scored every morning, each one as two currencies rather than one line.
Correlation is just a shared leg
A currency pair is not one thing. It is two currencies, and the price is the tug of war between them. When two pairs share a currency, they share whatever is happening to it, and that is the whole of what people call correlation.
So EUR/USD and GBP/USD move together for as long as the dollar is the loudest voice in both. The moment the European Central Bank meets and the Bank of England does not, the euro leg starts doing its own thing and the two drift apart. The correlation did not break. The driver changed.
That is why a fixed correlation number is worth less than it looks. It tells you what has been true over the last stretch, not which currency is carrying the pair right now, and it is the second thing that decides what happens next.
The check before your second trade
- Write both trades out as four currencies, not two pairs.
- A currency that appears twice on the same side is your real position, at double the size.
- A currency that appears on both sides cancels out, and you are left with a cross you did not choose.
- If neither happens, the two trades are genuinely separate ideas and your risk is what you think it is.
It is the same arithmetic a prop firm applies to your account when it adds up exposure, so it is worth doing first.
What moves with what, and when it stops
This table is on purpose not a set of coefficients. It says what two pairs share and therefore what has to be true for them to move together, which survives a change of regime in a way that a rolling number does not.
| Pair | Against | What they share | They move | They split when |
|---|---|---|---|---|
| EUR/USD | GBP/USD | The dollar, on the same side | Together, while the dollar is doing the work | As soon as the euro or sterling gets its own story, such as a central bank meeting on one side only |
| EUR/USD | USD/CHF | The dollar, on opposite sides | Almost mirrored: when one rises the other tends to fall | When the franc is being bought as a haven rather than sold against the dollar |
| AUD/USD | NZD/USD | The dollar, and a similar risk profile | Together in nearly every risk-on and risk-off move | Around their own central banks, and when commodity prices split the two economies |
| USD/CAD | Oil | The Canadian economy's biggest export | Usually opposed: a higher oil price tends to weigh on USD/CAD | When the dollar is being repriced for its own reasons, which overrides the oil link |
| USD/JPY | Equity indices | The risk mood, and the yen's role as a funding currency | Often together, because a calm market sells the yen to fund other positions | When the Bank of Japan itself is the story, or in a haven bid that buys the yen back |
| EUR/GBP | Anything with the dollar | Nothing | Rarely, which is exactly why it is useful | By design: a cross with no dollar leg is the cleanest way to trade one European story against another |
A ranking answers it better than a matrix
If correlation is a shared leg, then the useful thing to know is what each leg is doing. That is what a strength ranking is: all eight majors measured against the same basket, so you can see whether EUR/USD is rising because the euro is strong or because the dollar is weak. Those two look identical on a chart and they lead to completely different second trades.
We score the eight every morning and all 28 pairs between them, and every pair is shown as its two legs with the reason for each. When both legs of a setup pull the same way, the pair is worth the attention. When one leg is doing all the work, the pairs that share that leg are the same trade in different clothes.
The practical version: pick the widest gap between a strong currency and a weak one, take that pair, and leave the ones that share a leg with it alone. The pair scores and the strength ranking are both built for that question.
Questions about correlation
Why do currency pairs move together?
Because they share a currency. EUR/USD and GBP/USD both have the dollar on the same side, so while the dollar is the loudest voice in the market they rise and fall together. What people call correlation is nearly always one leg doing the work in two places.
Which forex pairs are most correlated?
The ones sharing a leg in the same direction, such as EUR/USD with GBP/USD, or AUD/USD with NZD/USD. The ones sharing a leg in opposite directions move against each other, EUR/USD against USD/CHF being the clearest. A cross with no dollar leg, such as EUR/GBP, is the least tied to the rest.
Where is your correlation table?
We publish what two pairs share and what has to be true for them to move together, rather than a rolling coefficient. A number from the last twenty days describes a regime that may already have ended, and it cannot tell you which of the two currencies is carrying the pair today. The structural version keeps working when the driver changes.
How do I avoid taking the same trade twice?
Write both trades out as four currencies instead of two pairs. A currency that appears twice on the same side is your real position at double the size, and one that appears on both sides cancels out. It is the same sum a prop firm does when it adds up your exposure. Prop firm rules
Does a strength ranking help with correlation?
It answers the question a matrix cannot: whether EUR/USD is rising because the euro is strong or because the dollar is weak. Those look identical on a chart and they lead to completely different second trades. We rank all eight majors against the same basket every morning for exactly that reason. The strength ranking