XAUUSD vs Gold Futures: What Changes in a Backtest?
Compare spot XAUUSD, GC and MGC: contract size, risk math, data feeds and costs. Choose the correct gold instrument before backtesting.
XAUUSD and GC futures both provide a way to study gold prices, but they are different instruments. XAUUSD labels gold quoted in US dollars, usually through a spot or broker-specific product. GC is an exchange-listed futures contract with standardized specifications and contract months. A familiar-looking chart does not make their execution or position sizing interchangeable.
If you want to backtest a gold setup, choose the instrument first. This guide explains the decisions that follow.
Compare the instrument, not just the price line
| Question | XAUUSD | GC gold futures |
|---|---|---|
| What are you looking at? | Gold quoted in dollars; check the actual provider/product | A standardized COMEX futures contract |
| Position size | Depends on the provider's units and lot convention | GC contract size is 100 troy ounces |
| Contract lifecycle | Depends on the spot/CFD arrangement | Dated contracts, with expiry and delivery rules |
| Historical feed | Provider-specific | Specific contract or a continuous series assembled from contracts |
| Cost model | Check spread, commission and any holding charges | Check commission, exchange fees, spread and slippage |
| One price move | Monetary result depends on size and multiplier | A $1 move is $100 per GC contract before costs |
CME's gold product overview describes GC and the smaller gold contracts. A broker's XAUUSD specification remains the source for that broker's lot size and charges.
Work through the same stop on two different products
Suppose a hypothetical gold entry is 2,400.00 and the planned stop is 2,397.50. The price distance is $2.50 per ounce.
For one GC contract, that distance is $250 of price risk before costs. For a hypothetical spot position representing ten ounces, it is $25. The price levels match, while the monetary exposure differs by a factor of ten.
The ten-ounce spot example is not a universal XAUUSD lot definition. Find the unit size in the instrument specification before copying the arithmetic. A platform's quantity field might count contracts, lots or another unit.
Keep risk in both money and R in your trading journal. Recording only “one gold trade” hides the difference.
Micro Gold is a third product
MGC is CME's Micro Gold futures contract, with a contract size of ten troy ounces. Its standard $0.10 price increment corresponds to $1 per contract, compared with $10 for GC. CME's micro metals specifications cover these products.
MGC is useful to understand when comparing contract exposure. It does not follow that a platform offering GC or XAUUSD also offers MGC. Verify the symbol list separately.
The GC guide includes contract calculations and a historical testing exercise. It owns the detailed GC topic; this comparison is about choosing the correct dataset and assumptions.
Match the times you are comparing
A move marked 08:30 on one chart may represent another moment on a chart with a different timezone. Align actual timestamps before comparing candles.
Then check each market's maintenance breaks and the provider's available data. A five-minute bar that straddles a missing-data interval should not be treated as if all underlying observations were present. Holiday hours and daylight-saving changes need checking for the dates under review.
If a strategy is defined around an economic release, use the event's actual timestamp on that date. “Always at this UTC hour” is a different rule from “at the scheduled US release.”
Understand continuous futures before testing a level
A continuous futures chart combines a sequence of dated contracts. Different providers can choose different rollover rules or adjust historical prices differently.
That matters for an absolute price level carried across a roll. Ask which underlying contract was represented, whether prices were adjusted, and whether the strategy requires a level from before the transition. If the dataset does not answer those questions, flag the affected period and limit the conclusion you draw from it.
Spot and futures prices can also differ. A signal observed on one product does not automatically establish that an order on the other could have filled at the same price. Keep their spread, commission and slippage assumptions separate too.
A clean way to compare two gold datasets
Use the same written rule on both datasets, but keep their results separate:
- Choose identical calendar dates and align their timestamps.
- Record available resolution and all missing intervals.
- Define entry and exit timing without looking ahead.
- Use each product's own units, multiplier and cost assumptions.
- Mark signals that occur on only one feed.
- Compare net R and drawdown as well as the raw number of signals.
For example, a completed-bar breakout might occur one bar earlier on one feed. Record that difference instead of moving the entry to make the tests agree. The backtesting guide explains how to preserve the original rules while investigating a discrepancy.
Which gold products can you practice on TestMax?
At the September 2026 content check, TestMax's public inventory lists XAUUSD as Gold Spot and GC as Gold (COMEX). GC requires Pro. XAUUSD has no paid instrument restriction, within the Free plan's limited recent data window. MGC is not listed. Availability and plan details can change, so check the current selector and pricing page before choosing your test.
The listed stored resolution for both gold instruments is ten seconds at that check. This does not promise finer observed price detail or mean every plan can select a seconds chart. Pick a supported timeframe suitable for the question you are testing.
Create a TestMax account to start with an available gold replay, or explore GC backtesting if exchange futures are your focus. Write down which product you selected before the first simulated order. That one line prevents a surprising number of misleading comparisons.