Technically you can start trading gold with $100 at most brokers. Realistically, the number that matters is risk per trade, not deposit size. If you risk 1% per trade with a typical gold stop, you need roughly $500–$2,000 to size positions sensibly without a single loss doing real damage.
Brokers advertise low minimums because it gets accounts opened. But a $100 account trading 0.10 lots on gold is risking about $10 per $1 move — a normal 3-dollar swing wipes 30% of the account. The account didn't fail because it was small; it failed because the position was enormous relative to it.
Decide your risk per trade first (1% is a common ceiling; many professionals use less). On XAUUSD, a 0.01 lot position gains or loses about $1 per $1 move in price. If your stop is $3 away and you're risking 1% of a $1,000 account ($10), you can afford roughly 0.03 lots. Work backwards from the stop — never forwards from greed.
Gold moves further than most currency pairs. Daily ranges of $20–$40 are routine, and news can produce that in minutes. A stop placed too tight gets taken out by ordinary noise, so gold entries typically need wider stops — which means smaller position sizes for the same risk.
If you're learning, start on demo until your process is repeatable. When you go live, an account of $500–$2,000 lets you trade the minimum 0.01 lot while keeping risk per trade around 1% with a realistic gold stop. Below that, the minimum lot size forces you to over-risk.
You can open an account, but the minimum 0.01 lot risks roughly $1 per $1 move — on a $100 account that's 1% per dollar of movement, which is far too much for a normal gold stop.
Size from your stop distance: risk amount ÷ (stop distance in dollars × 100) = lots. Never pick a lot size first.
Gold is more volatile than most major pairs, so the same lot size carries more dollar risk. That demands smaller positions, not more courage.