How Currency Pairs Work in Forex Trading

In forex, you never trade a single currency on its own. Every trade involves exchanging one currency for another, so prices are always shown as a currency pair. Once you understand how a pair is written and what buying or selling it means, every forex quote becomes much easier to read.

Reading a currency pair

A pair is written as two three-letter currency codes separated by a slash, such as EUR/USD. The codes follow the ISO 4217 standard: EUR for the euro, USD for the US dollar, GBP for the British pound, JPY for the Japanese yen, and so on.

Assume EUR/USD is quoted at 1.0850 (illustrative). This tells you:

• One euro (the first currency) costs 1.0850 US dollars (the second currency).
• If the quote rises to 1.0900, the euro has strengthened against the dollar, because each euro now buys more dollars.
• If the quote falls to 1.0800, the euro has weakened against the dollar.

The first currency is called the base currency and the second is the quote currency. The next lesson, Base and quote currency, looks at these roles closely.

What buying and selling a pair means

Because a pair contains two currencies, every trade is two transactions at once:

If you think the euro will strengthen against the dollar, you would buy EUR/USD. If you think the euro will weaken, or that the dollar will strengthen, you would sell EUR/USD. With most retail brokers you can sell a pair without owning the base currency first; this is called going short.

Major, cross and exotic pairs

Pairs are usually grouped by how actively they trade.

Major pairs include the US dollar and another heavily traded currency. The pairs most often listed as majors are EUR/USD, USD/JPY, GBP/USD, USD/CHF, AUD/USD, USD/CAD and NZD/USD. They tend to have deep liquidity and narrow spreads.

Cross pairs pair two major currencies without the US dollar, such as EUR/GBP, EUR/JPY or GBP/JPY. See cross currency pair. Their spreads are often a little wider than the majors.

Exotic pairs combine a major currency with the currency of a smaller or emerging economy, such as USD/TRY (Turkish lira) or USD/ZAR (South African rand). An exotic pair can have wider spreads, lower liquidity and sharper price jumps.

Market convention: which currency comes first?

The order of a pair is set by market convention, not by choice. The euro is normally quoted first against other currencies, followed broadly by the pound, the Australian and New Zealand dollars, and then the US dollar. That is why you see EUR/USD and GBP/USD, but USD/JPY and USD/CAD.

You could express any rate the other way round by taking its inverse. With EUR/USD at 1.0850, one dollar is worth 1 ÷ 1.0850 = 0.9217 euros (rounded to four decimal places). Brokers, however, quote the conventional direction, so it pays to get used to it.

Worked example: a trade on GBP/USD

Assume GBP/USD is quoted at 1.2700 (illustrative). A trader expects the pound to strengthen and buys 10,000 units of GBP/USD.

Scenario A: the pair rises to 1.2760. Price change = 1.2760 − 1.2700 = 0.0060. Profit = 0.0060 × 10,000 = $60.

Scenario B: the pair falls to 1.2650. Price change = 1.2650 − 1.2700 = −0.0050. Loss = 0.0050 × 10,000 = $50.

Notice that the profit or loss is in US dollars, the quote currency. If your account is held in another currency, the broker converts the result. Costs such as the spread would reduce Scenario A's profit and add to Scenario B's loss. Small moves like these are measured in pips; the Pip Calculator helps you work out what each pip is worth.

Why pair choice matters

Different pairs behave differently. Some react strongly to particular central banks or commodity prices, some move more during certain trading sessions, and some have higher trading costs. Beginners often find it easier to focus on one or two liquid major pairs while learning, rather than jumping between many.

Common mistakes

• Reading the pair backwards. USD/JPY at 150.00 means one dollar buys 150 yen, not the other way round.
• Forgetting the second currency. Selling USD/JPY is also a bet that the yen strengthens.
• Assuming all pairs cost the same to trade. Exotic pairs can have much wider spreads.
• Ignoring the currency of profit. Gains and losses arrive in the quote currency first.

Summary

A currency pair shows the price of the first (base) currency in units of the second (quote) currency. Buying the pair means buying the base and selling the quote, and selling means the reverse. Pairs fall into majors, crosses and exotics, which differ in liquidity and cost. Every trade carries the risk that the pair moves against you, so understanding the quote is the first step toward managing that risk.