HSBC - "US: QE = USD negative: Resultant “risk on” mood takes us to higher yielding more risky currencies. “Risk off” and the USD’s safe haven status kicks in.
Eurozone: QE = EUR positive: Non-conventional easing as lowering the probability of EUR default and disintegration, thereby boosting the EUR.
Japan: QE = mild JPY positive: JGB purchases have little JPY effect, but equity market boost encourages foreign capital inflows.
UK QE = GBP neutral: Little currency impact as un-conventional monetary easing seen as an appropriate mirror to the ongoing tightening in fiscal policy.