How often should I re-test a gold strategy?

Review expectancy monthly and re-run the full test quarterly, or immediately after any structural change in gold volatility such as a sustained move above the average true range band you tested in.

Do gold strategies decay faster than FX strategies?

Typically yes, because gold reprices hard around macro shifts in real yields and the dollar, so the regime it depends on rotates more often.

Should I re-optimise parameters when performance drops?

Not first. Re-optimising into a drawdown is how curve fitting happens. Identify the changed condition first; if you cannot name it, cut size and wait.

WHY GOLD STRATEGIES DECAY

Gold strategy decay is caused by regime change, volatility expansion, spread and cost creep, or crowding at obvious levels, and each leaves a distinct signature in a trade journal.

Decay differs from ordinary drawdown because the distribution of results shifts rather than a normal losing run occurring within it.