Is 30 trades enough to judge a gold strategy?

It is enough to catch obvious execution or discipline problems but not enough to estimate a win rate reliably — the confidence interval around a win rate built from 30 trades is still wide enough to include both a losing strategy and a genuinely good one.

Why does one big winning trade distort a small gold sample so badly?

Because gold's tail events — a CPI surprise, an FOMC surprise, a geopolitical headline — can produce a single trade result many times the size of an ordinary trade. In a sample of 20 or 30 trades, one such result can dominate the total profit or loss and misrepresent the strategy's normal behaviour.

Do I need 100 trades even for a slow swing-trading gold strategy?

No — swing strategies that take a handful of trades a month are usually judged from a smaller trade count, commonly 30 to 50, because gathering 100 would take years. The trade-off is that macro coverage across CPI, NFP and FOMC cycles becomes the dominant requirement instead of raw count.

What is a Wilson interval and do I need to calculate it myself?

It is a statistical method for estimating the plausible range of a true win rate given an observed win rate and a trade count. You do not need to compute it by hand to use the concept: the practical takeaway is that any win rate quoted from fewer than 100 gold trades should be treated as approximate, and the approximation improves substantially by 100 trades and again by 300.

Can I reach a valid sample faster by trading a lower timeframe?

Partly. A lower timeframe generates trades faster, but spread and slippage take a larger share of a smaller average move, so you are testing a strategy with a different cost profile, not the same strategy sampled more quickly.

What should I do if my sample size target is met but I have not seen an FOMC decision yet?

Keep testing under the unchanged rule set until an FOMC decision, and ideally two, has passed through the sample. A strategy untested around a rate decision has an unmeasured failure mode sitting in the one event most likely to move gold sharply against an unprepared position.

SAMPLE SIZE ON GOLD

How many gold trades are needed before a result is trustworthy depends on two separate requirements: trade count and macro coverage. Trade count controls how tightly a win rate or expectancy estimate is bounded by variance, while macro coverage controls whether the sample has actually been exposed to the CPI, NFP and FOMC conditions that periodically dominate XAUUSD price action.

As a floor, intraday XAUUSD strategies need roughly 100 trades and swing strategies need 30 to 50, but neither is sufficient on its own without at least three CPI releases, three NFP releases and one FOMC decision inside the sample window. Twenty or thirty trades can reveal gross execution problems but cannot reliably separate a real edge from ordinary variance, particularly when a single large gold move can dominate a small sample.

The Wilson score interval is the standard concept for expressing how much uncertainty surrounds an observed win rate at a given trade count, and its practical lesson for gold traders is straightforward: the interval is wide and largely uninformative below roughly 100 trades, narrows meaningfully by 100, and becomes tight enough to support a funding decision only once several hundred trades have accumulated under an unchanged rule set.