What Is XAUUSD and How Does Gold Trading Work?

The short answer

XAUUSD is the price of one troy ounce of gold, measured in US dollars. If the quote reads a given number, that is how many dollars one ounce costs at that moment. When traders talk about "trading gold" in a currency-trading account, this is almost always the instrument they mean.

The rest of this article explains why it is written that way, what actually makes it move, and what happens when you place a trade on it.

Why gold has a currency code

Currencies have three-letter codes under the ISO 4217 standard: USD, EUR, JPY. Precious metals have them too, beginning with X because they are not issued by any country — XAG for silver, XPT for platinum, XPD for palladium. XAU is the code for gold: X followed by Au, gold’s chemical symbol, which comes from aurum, the Latin word for it.

Writing gold as XAU lets it be quoted in exactly the same format as a currency pair. EURUSD tells you how many dollars one euro buys; XAUUSD tells you how many dollars one ounce of gold costs. That is convenient for the trading software, and it is why gold sits in the same list as currency pairs on most retail platforms.

It is also where a common misunderstanding begins. Gold is quoted like a currency pair, but it is not one. There is no central bank setting gold's interest rate and no government issuing it. How gold differs from forex covers why that matters in practice.

Reading the quote

Like a currency pair, XAUUSD is shown with two prices:

• Bid — the price at which you can sell.
• Ask — the price at which you can buy.

The ask is always higher than the bid, and the gap between them is the spread. You buy at the ask and sell at the bid, so a position that is opened and closed instantly, with no price movement at all, still loses the spread. That is a cost of doing business, and on gold it tends to widen when the market is busiest with news or quietest between sessions.

A ratio moves from both ends

This is the single most useful idea in this article. Because XAUUSD is gold divided by dollars, the quote moves when either side moves:

• Gold becomes more valuable in global terms → XAUUSD tends to rise.
• The dollar strengthens against other currencies → XAUUSD tends to fall, even if gold's global value is unchanged.
• Both happen at once → the effects may cancel out, and the chart shows very little.

In practice that means a gold chart is never only about gold. When XAUUSD moves sharply, one of the first questions worth asking is whether the dollar moved too. The wider set of forces behind the price is covered in what moves the price of gold.

What a gold trade involves

Placing a trade on XAUUSD through a typical retail broker involves four ideas.

Direction

Buying (going long) is a position for XAUUSD to rise. Selling (going short) is a position for it to fall. With a CFD you can sell without owning anything first, because you are trading a contract rather than the metal.

Size

Positions are measured in lots. Many retail providers define one standard lot of XAUUSD as 100 troy ounces, with smaller sizes such as 0.1 or 0.01 lots available — but this is not universal, and it is the single most important detail to check in your own platform's contract specification.

Size decides what a price move is worth. As a purely arithmetic illustration: if a position covers 100 ounces, every one-dollar change in the price of an ounce changes the position's value by 100 dollars. A position of one ounce changes by one dollar for the same move.

Margin and leverage

Most gold CFDs are traded on margin. You deposit a fraction of the position's full value and the broker lends the rest in effect. This is leverage, and it cuts both ways: the profit or loss is calculated on the full position, not on the margin you put down. A modest move against a large position can consume a large share of an account.

Costs

Beyond the spread, you may pay a commission, and holding a leveraged position overnight usually means a financing charge or credit, often called a swap. These vary by provider and account.

When XAUUSD trades

Gold is traded in several major centres rather than on a single exchange — chiefly the London over-the-counter market, the US futures market and the Shanghai Gold Exchange, which between them account for most global volume. Because those centres sit in different time zones, gold can be traded for most of the day through the working week. Retail XAUUSD hours are set by each provider, often with a short daily break, and your platform lists them under the symbol’s trading sessions.

Activity is not even across the day. Spreads tend to widen between the main trading sessions, when fewer participants are active, and in the run-up to major economic releases — and the minutes around a major US release can bring fast, jumpy prices.

Where to go next

XAUUSD is simple to define and demanding to trade. If this is your starting point, the complete beginner's guide to gold trading puts the instrument, its drivers and its risks in order. Before placing any trade, read how to manage risk when trading gold, which shows how to work out a position size rather than guess one.