Why the euro-dollar FX rate moves
What drives the most important currency pair? There are various factors, but conventional wisdom says rate differentials are key: when the ECB was tightening in 2008 and the US was fighting the subprime crisis, for instance, the euro soared as capital chased higher yields.
This visualisation is the result of a rolling regression model we built, attempting to find correlations that explain why EUR/USD moved at a given point in time. We tracked two swap spreads. One is a proxy for the perceived future of rate differentials; the other is for which currency is losing more value to inflation. We added Brent crude – ECB research found that pricier oil is correlated with USD weakness – and we added a MSCI spread tracking whether US or European equities outperformed.
According to this model, inflation is having little influence at the moment. But future rate differentials have a substantial negative influence: if the spread moves in Europe’s favour, the euro strengthens.
Meanwhile, spreads between equity markets have the opposite effect: if US stocks underperform their European counterparts, that tends to strengthen the dollar. This could be related to the “dollar smile” theory: consider a “risk-off” market, where a selloff in US tech stocks coincides with a global flight to safety in the form of US Treasuries and USD.
The second panel shows each factor’s contributions to weekly returns – and also indicates the generally lower volatility in 2023 versus the 2022 “King Dollar” era.