USDCHF: the mirror image that isn't quite a mirror

[Shadow Trader]

USDCHF often looks like an upside-down EURUSD. Euro up, franc up, so USDCHF tends to fall when EURUSD rises. Many traders treat them as inverse twins. The resemblance is real, but the differences matter.

The franc has safe-haven characteristics, so during sharp risk-off episodes it can strengthen even when the euro weakens, which breaks the mirror. The Swiss National Bank also intervenes at times, adding policy-driven moves that EURUSD doesn't share.

Spreads on USDCHF are typically a bit wider than on EURUSD, and ranges often smaller, so cost relative to movement is less favourable.

Some use USDCHF as a confirmation tool: when EURUSD breaks a level and USDCHF breaks in the opposite direction with similar strength, the dollar move looks genuine. When they diverge, something pair-specific is happening.

Trading both at once, in opposite directions, mostly duplicates exposure and pays two spreads, a point that's easy to forget.

A useful measurement: calculate the rolling 30-minute correlation between EURUSD and USDCHF. In normal times it sits near minus 0.9. When it drops toward minus 0.6 or less, something other than the dollar is driving at least one of them. That divergence tends to appear around Swiss news, risk-off bursts and SNB commentary.

Knowing when the mirror is broken is worth more than knowing when it works.

Does USDCHF get used as a confirmation for EURUSD signals, and has the divergence ever been informative?