Correlation in forex trading describes how closely two currency pairs move together. Because every pair is made of two currencies, and many pairs share one, trades that look separate on screen can be the same bet underneath. Knowing the correlation between your open positions is how you avoid doubling your risk without meaning to.
Quick answer: what is correlation in forex trading?
It is a measure, from -1 to +1, of how closely two pairs’ price changes move together. Near +1 they rise and fall together; near -1 they move in opposite directions. Pairs that share a currency are often correlated, so holding several can multiply one exposure. Readings change over time, so check them regularly.
What correlation in forex trading measures
The usual measure is the Pearson correlation coefficient, calculated on returns (the change from one bar to the next), not on price levels. Two pairs can both trend upwards over a year and still show a weak correlation if their day-to-day moves are unrelated.
A correlation table needs two settings: the timeframe and the lookback, meaning how many bars it covers. A reading over 20 daily bars can differ sharply from one over 100, so always check both before relying on a number. For how correlation fits across indices, metals and crypto, see our guide to diversifying a trading portfolio with uncorrelated assets; here we stay inside forex.
Why currency pairs move together
The main reason is shared legs. EUR/USD and GBP/USD both have the US dollar as the quote currency, so a broad dollar move pushes both the same way. The dollar is everywhere: the Bank for International Settlements’ 2025 survey of foreign exchange turnover found it on one side of 89.2% of all trades in April 2025.
Other links come from shared drivers. The Australian and New Zealand dollars both respond to commodity prices and global growth, and safe-haven currencies such as the yen and Swiss franc often strengthen together when markets turn nervous. Our guide to what moves the US dollar covers the biggest shared driver, and our guide to intermarket analysis for beginners shows how gold and the pound can respond to the same mood.
Crosses are built from the majors
A cross such as EUR/GBP is, in effect, EUR/USD divided by GBP/USD. That makes it mathematically linked to both majors, which matters when you combine it with them, as the worked example below shows.
How to read a correlation table
The figures below are illustrative bands, not current market readings. Correlations between real pairs move around, so take live numbers from a table on the timeframe you trade.
| Coefficient (illustrative) | What it suggests | How we treat it |
|---|---|---|
| +0.8 to +1 | Moves closely together | Count as one position |
| +0.5 to +0.8 | Often moves together | Reduce combined size |
| -0.5 to +0.5 | Weak or no relationship | Treat as separate |
| -0.8 to -1 | Moves in opposite directions | Same-direction trades largely cancel |
Direction matters as much as the number. Two pairs with a strongly negative correlation become one doubled position if you buy one and sell the other. If you are unsure how base and quote currencies decide direction, read our guide to going long and short in forex.
Netting your exposure by currency
A correlation table is useful, but there is a simpler check that works without one: split each position into its two currency legs and count them. Buying EUR/USD means long euro and short dollar; selling USD/CAD means short dollar and long Canadian dollar.
- List every open and planned position.
- Write each as a long leg and a short leg.
- Count how many times each currency appears on the same side.
- If one currency carries more risk than your limit, drop or shrink a trade before entry.
This catches overlap that a table can hide, especially when crosses are involved. It also shows when two trades cancel out, so you pay two spreads for little net exposure. Deliberately opening opposite trades is a separate tactic, covered in our guide to hedging in forex trading.
Worked example: three trades, one dollar bet
This example is hypothetical. On a £10,000 account we risk £50 per trade and have three setups: long EUR/USD, long GBP/USD and short USD/CAD. Each one, alone, follows our rule for how much to risk per trade.
Split into legs, all three are short the US dollar. A broad dollar rally, after a strong data release, could stop out all three together, a £150 loss, or 1.5% of the account, on one idea. In practice they behave closer to one £150 trade than three £50 trades.
Now suppose we swap long GBP/USD for short EUR/GBP, hoping for something different. Short EUR/GBP is short euro and long pound. Added to long EUR/USD, the euro legs cancel, and what remains is long pound and short dollar: the same exposure as the GBP/USD trade we removed, paid for with two spreads. Spread bets and CFDs are leveraged, so stacked exposure like this can cost far more than any single plan suggests.
The fix we use is to take the clearest of the dollar trades at full size, or split the £50 across two, and size each with our guide on calculating position size from your stop.
When correlation breaks down
Correlations are averages of the past, and they shift. The pound and the euro usually move together against the dollar, but on a Bank of England decision day GBP/USD can move sharply while EUR/USD barely reacts. Check the economic calendar for single-currency events before assuming two pairs will behave alike.
Shifts in central bank policy, elections and sudden moves in risk appetite can weaken or even flip a relationship for weeks. That is why we treat any reading as a snapshot rather than a rule.
Common mistakes with correlated pairs
- Using a second pair as confirmation, then trading both: two correlated setups are one idea taken twice.
- Calling opposite trades a hedge: long EUR/USD with long USD/CHF often cancels out while you pay costs on both.
- Reading one lookback only: a short window can show a link that a longer one does not.
- Forgetting crosses: a cross can quietly rebuild the exposure you thought you had closed.
Frequently asked questions
Which forex pairs are most correlated?
Pairs sharing a currency on the same side, such as EUR/USD and GBP/USD, or AUD/USD and NZD/USD, are often positively correlated. The strength varies over time, so check a current table before acting on it.
Is trading EUR/USD and GBP/USD together the same trade?
Not exactly, but both are partly a bet on the US dollar. Unless you have a clear view on the euro against the pound, treat them as one dollar exposure and size them together.
Can I hedge with negatively correlated pairs?
You can reduce net exposure, but you pay spreads and any overnight financing on both positions, and the relationship can break. Usually it is simpler to trade a smaller size on one pair.
What lookback should a correlation table use?
Match it to how long you hold trades. Swing traders might compare a few weeks of daily bars with a few months, while day traders look at intraday timeframes.
Next steps
Correlation limits sit inside a wider set of rules; see our guide to building a rules-based risk model. If you are still choosing a market, start with the best forex pairs for beginners in the UK.
Building a rules-based risk model is part of our price action trading course, and the basics section is free to start.
This article is for education only and is not financial advice. Trading leveraged products such as CFDs and spread bets carries a high risk of losing money.
