Forex Symbols Explained: ISO Currency Codes, Pair Categories & Cheat Sheet

Every transaction in the foreign exchange market involves the simultaneous buying of one currency and selling of another. Because of this dual nature, currencies are never traded in isolation—they are quoted in standardized combinations known as forex symbols or currency pairs.

Understanding how these symbols are structured is essential for interpreting price quotes, calculating pip values, and managing order execution costs.

What is a Forex Symbol?

A forex symbol is a standardized six-letter abbreviation representing the exchange rate between two national currencies. It follows the international ISO 4217 standard, where the first three letters represent the Base Currency and the last three letters represent the Quote (Counter) Currency.

For example, in the forex symbol EUR/USD:

• EUR is the Base Currency (Eurozone).

• USD is the Quote Currency (United States Dollar).

If EUR/USD is quoted at 1.0850, it means that 1 Euro is equal to 1.0850 US Dollars.

How Currency Symbols Are Constructed (The ISO 4217 Standard)

Currency codes follow a three-letter standard established by the International Organization for Standardization (ISO):

• First two letters: Represent the country code (e.g., US = United States, GB = Great Britain, JP = Japan).

• Third letter: Represents the first letter of the currency unit (e.g., D = Dollar, P = Pound, Y = Yen).

Examples:

• USD = US (United States) + D (Dollar)

• GBP = GB (Great Britain) + P (Pound)

• CAD = CA (Canada) + D (Dollar)

• AUD = AU (Australia) + D (Dollar)

• JPY = JP (Japan) + Y (Yen)

• CHF = CH (Confoederatio Helvetica / Switzerland) + F (Franc)

The Three Categories of Forex Pairs

Forex symbols are divided into three distinct classes based on daily trading volume, market liquidity, and broker spreads.

1. Major Currency Pairs

Majors are the most heavily traded pairs in the world. They always pair the US Dollar (USD) with another dominant global economy.

• Key Characteristics: Immense liquidity, virtually no slippage, and the lowest bid/ask spreads (often 0.0 to 1.0 pip).

• Core Pairs: EUR/USD, GBP/USD, USD/JPY, USD/CHF, AUD/USD, USD/CAD, NZD/USD.

2. Minor Currency Pairs (Crosses)

Minor pairs—commonly called currency crosses—consist of major global currencies traded against each other without the US Dollar.

• Key Characteristics: Healthy liquidity and active daily volatility, though spreads are slightly wider than majors.

• Core Examples: EUR/GBP, EUR/JPY, GBP/JPY, AUD/JPY, EUR/AUD.

3. Exotic Currency Pairs

Exotic pairs match a major currency (usually USD or EUR) against the currency of a developing or emerging market economy.

• Key Characteristics: Thin liquidity, wide spreads, high overnight swap rates, and sensitivity to geopolitical events.

• Core Examples: USD/ZAR (South African Rand), USD/TRY (Turkish Lira), USD/MXN (Mexican Peso), USD/SGD (Singapore Dollar).

Forex Symbols Quick-Reference Matrix

Symbol	Base / Quote	Pair Category	Trader Nickname	Liquidity & Spread Tier
EUR/USD	Euro / US Dollar	Major	Fiber	Tier 1 (Lowest Spread)
GBP/USD	British Pound / US Dollar	Major	Cable	Tier 1 (High Liquidity)
USD/JPY	US Dollar / Japanese Yen	Major	Gopher	Tier 1 (Tight Spreads)
USD/CAD	US Dollar / Canadian Dollar	Major	Loonie	Tier 1 (Commodity Linked)
AUD/USD	Australian Dollar / US Dollar	Major	Aussie	Tier 1 (High Volatility)
NZD/USD	New Zealand Dollar / US Dollar	Major	Kiwi	Tier 2 (Moderate Volume)
USD/CHF	US Dollar / Swiss Franc	Major	Swissie	Tier 2 (Safe Haven)
EUR/JPY	Euro / Japanese Yen	Cross / Minor	Yuppy	Tier 2 (Intraday Momentum)
GBP/JPY	British Pound / Japanese Yen	Cross / Minor	The Beast / Guppy	Tier 2 (Fast Trends)
USD/TRY	US Dollar / Turkish Lira	Exotic	—	Tier 3 (Wide Spread / High Risk)

Trading Considerations: How to Choose Which Symbol to Trade

Institutional volume is not distributed evenly across all currency symbols. When building your trading watchlist, consider these practical execution factors:

1. Transaction Costs (Spreads & Slippage): Scalpers and intraday price action traders should focus on major pairs like EUR/USD and USD/JPY where spreads remain tightest throughout the London and New York sessions.

2. Order Placement Precision: High-volatility crosses like GBP/JPY require wider stop-loss margins compared to USD/CHF due to rapid pip expansion.

3. Session Alignment: Currency symbols move most aggressively when the local financial centers of their constituent currencies are open. For example, trade AUD/USD during the Asian session or EUR/USD during the London/New York overlap.

(Related reading: Learn how to execute pending and market orders on these pairs in our detailed guide on types of forex orders: market vs pending orders.)