Traders who move from EURUSD to Gold with the same lot size and stop distance usually learn the difference quickly. XAUUSD is a different instrument and deserves its own settings.
Range
Gold's typical daily range, measured as a percentage of price, is often a multiple of that of a major currency pair. A stop that sits comfortably outside normal noise on EURUSD may sit well inside it on Gold, and will be hit by ordinary movement.
Size follows stop distance
If the stop must be wider, the position must be smaller to keep the amount at risk the same. Decide the amount you are prepared to lose on the trade first, place the stop where the trade idea is invalid, and let those two numbers set the size. Never the other way round.
News
Gold reacts strongly to interest-rate expectations, inflation data, the US dollar and geopolitical events. Around scheduled releases, spreads can widen and price can gap through a stop. Many systematic traders simply do not open new Gold positions in the minutes around major releases.
Contract details
Contract size, minimum lot, margin requirement and swap for XAUUSD differ between brokers and account types. Check your own broker's specification before calculating risk.
In practice
- Measure current volatility, for example with ATR, before choosing a stop.
- Scale position size to that stop.
- Set a daily loss limit and keep to it.
- Treat scheduled news as a risk event, not an opportunity by default.