Lesson 27 of 69
Currency correlation basics
8 min read
Chapter checkpoints
0/4- How correlation is measured
- The classic examples
- Why this is a risk lesson, not a strategy lesson
- Rules that keep correlation from hurting you
Optional — tick a chapter as you finish it to keep your place inside this lesson.
is simply the tendency of two markets to move in a related way. In forex it happens for an obvious reason: every pair is half a currency you are buying and half a currency you are selling, and the same currency shows up in many different pairs. Trade three pairs that all contain the US dollar and you have not diversified — you have taken the same dollar bet three times.
How correlation is measured
Correlation is scored between +1.0 and −1.0. A reading of +1.0 means the two pairs moved identically over the period measured, −1.0 means they moved in exact opposition, and 0 means there was no reliable relationship at all. Anything beyond roughly +0.7 or −0.7 is strong enough to matter for your risk.
| Pair | EUR/USD | GBP/USD | USD/CHF | XAU/USD |
|---|---|---|---|---|
| EUR/USD | +1.0 | +0.9 | -0.9 | +0.6 |
| GBP/USD | +0.9 | +1.0 | -0.8 | +0.5 |
| USD/CHF | -0.9 | -0.8 | +1.0 | -0.4 |
| XAU/USD | +0.6 | +0.5 | -0.4 | +1.0 |
The classic examples
- EUR/USD and GBP/USD move together (strongly positive). Both are a European currency against the dollar, so when the dollar weakens both usually rise.
- EUR/USD and USD/CHF move opposite (strongly negative). The dollar is the base in one and the quote in the other, and the euro and Swiss franc trade closely together.
- AUD/USD and NZD/USD move together — two commodity currencies from the same region, driven by the same risk appetite.
- XAU/USD (gold) is loosely negative with the dollar: a weaker dollar usually supports gold, though not reliably enough to trade blind.
- USD/CAD and oil move opposite: Canada exports oil, so rising crude tends to strengthen the Canadian dollar and pull USD/CAD down.
Correlation is not fixed
These relationships tighten and loosen. During a Fed decision almost everything becomes a dollar trade and spike toward 1.0; during a quiet Asian session they can drift to zero. Treat any number you read as a description of the recent past, not a law.
Why this is a risk lesson, not a strategy lesson
The danger is arithmetic. You risk a disciplined 1% on EUR/USD, 1% on GBP/USD and 1% on AUD/USD, and you believe you are risking 1% three times across three different markets. You are not. All three are short-dollar positions, so a single strong dollar print takes all three stops at once — the real exposure was one 3% trade wearing three different names.
| What you opened | What you think you risk | What you actually risk |
|---|---|---|
| Buy EUR/USD 1% + Buy GBP/USD 1% | 1% each, diversified | ~1.9% on one short-dollar bet |
| Buy EUR/USD 1% + Sell USD/CHF 1% | Two separate trades | ~1.9% — these are near-duplicates |
| Buy EUR/USD 1% + Buy USD/CHF 1% | Two separate trades | Close to 0% — the positions cancel out, you pay two spreads for nothing |
| Buy EUR/USD 1% + Buy USD/JPY 1% | 2% total | Partly offsetting — one long dollar, one short |
The hedge that is not a hedge
Buying EUR/USD and buying USD/CHF at the same time feels clever and does almost nothing except cost you two and two charges. If you want less exposure, take a smaller position — do not build it out of opposing trades.
Rules that keep correlation from hurting you
- 1Before opening a second trade, which currency both positions share and on which side. If the answer is the same currency on the same side, you are adding to an existing trade.
- 2Cap total risk per currency, not per pair. A 2% ceiling on all dollar-exposed trades combined is a simple, effective rule.
- 3If you genuinely want two setups, halve the size of each so the combined risk equals one normal trade.
- 4Prefer the cleaner chart. When EUR/USD and GBP/USD offer the same setup, take the one with the better structure rather than both.
- 5Check the correlation heatmap on this site before your session so you know what is currently moving together.
See it live
The Danipips correlation heatmap shows current relationships across the majors, metals and crypto. Use it as a pre-trade check: green blocks are pairs that will win or lose together, red blocks are pairs that will offset each other.
Size correlated trades as one trade
If you take two strongly correlated setups, run the calculator with half your usual risk on each so the pair of them still totals 1%.
Related lessons & next steps
Key takeaways
- Correlated pairs move together — EUR/USD and GBP/USD are largely dollar bets.
- Two same-direction trades on correlated pairs is one double-sized trade.
- Negative correlation means positions can cancel each other out.
- Cap your total exposure to a single driver, such as the US dollar.
Knowledge check
3 quick questions — your best score is saved to your progress.
1. What does a strong positive correlation between two pairs mean?
2. Why is opening the same-direction trade on two correlated pairs risky?
3. How should correlation change your position sizing?
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