What’s Driving the Dollar’s Decline?

A recent Bloomberg article, (Misfiring Models Leave Wall Street Currency Traders Flying Blind) raised some important questions about the challenges facing currency markets today. Here, we pick up where the article left off, examining the forces behind the dollar’s recent moves and addressing the gaps in conventional theories.

It’s not about carry. US interest rates are down year to date, but so are the rates of most other major global currencies (except for the yen). In fact, US rates have actually declined by less than the average interest rate drop among the G10.

Could it be purchasing power parity (PPP) making a comeback? The dollar has long been overpriced based on most models, which helps explain the yen’s recent rise, given it was 36% undervalued against its PPP equilibrium. But what about the Swiss franc? It’s now 20% overvalued on a PPP basis yet has climbed roughly 13% against the dollar this year, making it the second-best performer. Overvaluation alone doesn’t typically explain such a sharp dollar downturn.

Does the answer lie in tariff turmoil? Before April’s  “Liberation Day,” tariffs were broadly expected to strengthen the dollar. The logic was simple: US trading partners would depreciate their currencies to offset the higher costs of exporting to the US. Yet the dollar remains below its pre-Liberation Day levels, unlike the rebound seen across most other US assets.

One intriguing possibility gaining attention is hedging. The theory here is that non-US investors have to remain invested in US assets, but are reducing exposure to US currency risk by selling dollars. And while this might contribute in part to the dollar’s decline, it doesn’t seem sufficient to explain its scale or breadth. For instance, Japanese life insurers, which are among the largest private holders of US assets, have reduced their hedge ratios to multi-year lows (Japanese Life Insurers Cut Bullish Yen Hedges to 14-Year Low - Bloomberg). Meanwhile, Taiwan life insurers have seen a slight uptick in hedging activity, though their levels remain low. For both, hedging is quite costly, because it is expensive to sell dollars when US short-term interest rates outpace local rates. 

And so it goes. While every theory has its gaps, there are some things that have worked:

First, some core “macro” inputs like growth forecasts and economic data surprises. These have had a good record so far this year for gauging the dollar’s moves. A currency, in some sense, is the sum total of the value of its economy, so macro data should be a primary driver of currencies.

Second, measures that quickly capture shifts in the risk environment. Risk sentiment has fluctuated sharply, particularly after the April 9 “pause” in reciprocal tariffs. Since then, positive trade news has repeatedly eased risk aversion, pulling the dollar lower.

This trend has become more pronounced in recent years. “Risk-off” events in currency markets have tended to be quite short, quickly swinging back to “risk-on” conditions. The days when investors could rely on holding the dollar, Swiss franc, and Japanese yen for months during bouts of risk aversion seem to be over. Or more precisely, the specific risk scenarios that favor these currencies have become increasingly rare. Instead, risk-off events are driven more by liquidity concerns and are often mitigated by policy intervention.

If “macro” and “risk” factors are performing well, that’s a pretty good sign. Currencies are never driven by just one factor, like carry. Relying on such models alone invites what the Bloomberg article aptly calls “misfires.” Successful strategies incorporate multiple factors to compensate when the usual triggers, like carry, falter.