Direct answer
In forex, major currency pairs are the most widely traded pairs in the market. They typically include the US dollar (USD) paired with other large, commonly traded currencies (for example, EUR/USD, GBP/USD, and USD/JPY).
All crosses refers to cross currency pairs—currency pairs where the two currencies are quoted against each other without USD on both sides (for example, EUR/GBP or AUD/JPY). In other words, a “cross” is about the quoting structure, not about the size of the two countries’ economies.
Explanation: how the terms work
A currency pair is written as Base/Quote. The base currency is the first currency in the pair, and the quote currency is the second.
Majors (major pairs) are best understood as a market convention: they are the pairs most people refer to when discussing the “core” of the forex market. A common defining feature is that USD is involved and the other currency is also among the most actively traded currencies.
Cross pairs are defined by what is missing: USD is not the pair’s direct reference currency. Instead, the price expresses how much of the quote currency you get for one unit of the base currency.
Because these are definitions used across the industry, exact membership can vary slightly by source (for instance, which less-common “crosses” are included in a given list). That means you should treat the concept as standard terminology, not a single universally identical list everywhere.
Example checks: grouping pairs by structure
Use two independent checks:
- Does USD appear in the pair?
- If USD is involved (for example, USD/JPY or EUR/USD), it is more likely to fall under “major” conventions.
- If USD is absent from both sides (for example, EUR/GBP), it is a cross.
- Is the pair quoted between two non-USD currencies?
- If yes, it fits cross currency (part of “all crosses”).
- If no, it is not a cross in the strict structural sense.
This approach avoids relying on any single “official” list and focuses on how the pair is constructed.
Limitations and uncertainty (and what you can verify)
- No single universal list: The term “majors” is a convention. Different market participants may list slightly different pairs, especially at the margins.
- Structure is clearer than classification: “Cross” is mostly about whether USD is included, which is easier to verify than “major” membership.
- Definitions do not imply outcomes: Knowing which pairs are majors or crosses does not indicate future price direction, volatility, or risk level.
- Independent verification: You can verify pair structure by checking the pair symbols themselves (for example, whether USD appears). For “major” lists, compare multiple reputable references because listings can differ.
If you want to narrow the scope further (for example, focusing on a particular region such as AUD-related crosses), you can use the same structural checks to define which pairs qualify as crosses and then apply whatever conventions your reference source uses for “major” vs “minor” classification.