Risk-on and risk-off: when the correlation between USD/JPY and equities flips

[Amanhasnoname]

USD/JPY often rises with equities, as the yen weakens when risk appetite is high. During certain stress events, however, the correlation can flip, with the dollar and the yen both strengthening, or with the yen rising on safe-haven demand while the dollar falls.

The relationship depends on the driver of the moment. If rates are the focus, USD/JPY follows US yields. If risk sentiment dominates, it follows equities. If an inflation shock arrives, the dollar side may behave differently.

Scalpers who use equities as a filter for USD/JPY may find the signal fails when the regime changes. A rolling correlation measured over a short window can show the shift.

Rather than assuming a fixed relationship, test it in rolling windows and use it only when it is stable. A sign flip in the correlation is itself a warning that the market's driver has changed.

The practical outcome is fewer trades during transition periods, when old relationships fail and new ones are not yet clear.

How stable has the USD/JPY and equity correlation been in the windows traded?