Strong Dollar Effect Explained: How Currency Moves Change Returns

You can be right about a foreign stock and still lose money. A strengthening U.S. dollar reduces returns from international investments for American holders, and that dynamic is playing out across multiple asset classes right now as the dollar maintains elevated levels against major currencies.

What Creates the Strong Dollar Effect on International Returns?

The strong dollar effect occurs when currency appreciation erodes gains from foreign investments. When you own international stocks, bonds, or funds, your returns depend on two factors: the performance of the underlying asset in its local currency, plus the exchange rate movement between that currency and the dollar.

The rate differential that sustains dollar strength is visible in today's data. The 3-month Treasury bill yield sits at 3.59%, while the 10-year Treasury yields 4.45%. Both rates sit well above comparable European benchmarks. The ECB's main refinancing rate was cut to 2.40% in April 2025, and markets expect further easing. That gap continues to pull capital toward dollar-denominated assets.

The mathematics work against international returns when the dollar strengthens. If a European stock rises 10% in euros but the euro falls 8% against the dollar, your dollar-denominated return shrinks to roughly 1.8%. This pattern repeats across regions as rate differentials persist.

How Different Asset Classes Respond to Dollar Strength

International equities show the most direct impact from currency movements. Today's market data illustrates the headwinds: the STOXX 50 declined 0.08%, the FTSE 100 fell 0.16%, and the Amsterdam AEX dropped 0.22%. European markets were weighed down in part by a deteriorating security picture on the continent. A Russian drone struck Romanian territory this week, a NATO member, an incident that rattled European confidence and underscored the proximity of conflict to core EU economies. With geopolitical risk rising in Europe, investors face both muted local returns and the currency drag of converting those returns back into dollars.

Bond markets present a double burden for international fixed-income holders during dollar strength periods. Not only do currency moves reduce returns, but elevated U.S. yields (the 10-year at 4.45%, the 30-year at 4.99%) make domestic bonds more attractive relative to foreign debt with lower yields. Money flows toward the higher coupon, reinforcing the dollar.

Commodities present mixed signals under dollar strength. Gold gained 1.36% today despite the strong dollar environment. That divergence likely reflects geopolitical risk premiums building as Ukraine launched drone strikes against a Russian oil facility and conflict escalated across the region. Oil, however, fell 1.73%, suggesting the supply disruption fears were offset by broader demand concerns.

Emerging markets face amplified pressure when the dollar strengthens. Indian markets fell 1.5% today (Nifty 50) while Brazilian stocks dropped 0.73%, reflecting how dollar strength often triggers capital outflows from higher-risk international markets. Colombia's upcoming elections, seen as a crucial test for the Latin American left, add political uncertainty that further discourages capital allocation to the region.

Why Rate Differentials Drive Currency Movements

Central bank policy divergence creates the foundation for sustained currency trends. With the 3-month T-bill yielding 3.59% and the ECB's main refinancing rate at 2.40% (and likely heading lower), investors face clear incentives to hold dollar assets.

This dynamic intensifies as inflation readings diverge. U.S. consumer prices continue running above the Fed's target on a year-over-year basis, maintaining pressure for higher rates, while European inflation has moderated toward the ECB's 2% goal. The result is a self-reinforcing cycle: rate differentials support dollar strength, which then reduces international investment returns, which discourages capital from leaving the U.S.

What International Fund Holders Are Seeing

Diversified international fund investors face the strongest currency headwinds during these periods. A fund holding European, Asian, and emerging market positions encounters multiple currency translations, each potentially reducing dollar returns. Today's data captures this neatly: the Vanguard Total International Stock ETF (VXUS) gained just 0.08%, and the developed-market VEA rose only 0.15%, while the emerging-market VWO was essentially flat at -0.03%. Compare that to the S&P 500's 0.22% gain or the Dow's 0.72% advance, and the drag becomes visible.

Unhedged international funds suffer most during sustained dollar strength. Currency-hedged funds attempt to eliminate this effect through derivatives, though hedging costs can reduce returns in different ways.

Sector-specific impacts vary significantly. Asian tech markets demonstrated this today with striking gains: South Korea's KOSPI surged 3.55% and Taiwan's TWII jumped 2.51%. The catalyst appears tied to continued momentum in the semiconductor supply chain and defense technology spending. The AUKUS announcement that the alliance will develop unmanned undersea vehicles, with Pentagon backing, reinforces the broader defense and advanced-tech spending cycle that benefits Asian chipmakers and component suppliers. Japan's Nikkei rose 2.53%, benefiting from similar tailwinds plus yen weakness that boosts export competitiveness. These moves show that strong fundamental catalysts can overcome currency headwinds, at least in the short term.

Economic Indicators That Signal Currency Trend Changes

Several indicators typically precede major currency reversals. The yield curve spread (the 10-year at 4.45% minus the 2-year, currently a positive but compressed gap) suggests markets are watching for potential Fed policy shifts ahead.

Labor market data provides another signal. Any significant deterioration in U.S. employment would likely prompt rate cuts, narrowing the differential that supports dollar strength.

Inflation trajectories between regions create the most reliable currency indicators. The current gap between U.S. and European inflation suggests dollar strength could persist until these metrics converge.

Digital asset markets may also be offering a signal. Bitcoin slipped today as ETF demand cooled, with analysts warning the downturn may extend. When speculative appetite cools across crypto, it sometimes reflects a broader tightening of dollar liquidity that reinforces the strong-dollar regime.

Portfolio Context for Currency Effects

Currency movements can overwhelm fundamental analysis. A well-researched European company with strong earnings growth may still produce negative dollar returns during sustained dollar strength. Geographic diversification, traditionally viewed as risk reduction, actually increases currency risk for dollar-based portfolios. This is the paradox investors are navigating right now.

Time horizon matters. Short-term currency movements often reverse, while fundamental economic divergences can sustain currency trends for years. The current rate differential environment suggests this cycle may persist longer than typical.

Asset allocation models typically assume currency effects average out over time. However, sustained trends like the current dollar strength can create multi-year periods where this assumption fails. Emerging market exposure amplifies both currency risk and potential returns, as these markets often experience larger currency swings but may offer compensation through higher growth rates when conditions normalize.

Current Signals

Today's data highlights several important patterns for currency watchers:

For those studying international markets, the key observation remains that currency effects currently outweigh many fundamental factors in determining dollar-denominated returns. This creates both challenges for international allocation and opportunities for those positioned for eventual currency normalization.

We continue tracking these developments across our research dashboard while building context through our ongoing market analysis to identify potential inflection points in currency relationships.

Research output, not investment advice. The material above is observational and educational. The operator of Observed Markets may hold personal positions in subjects studied here (disclosed at observedmarkets.com/conflicts-of-interest). Always consult an authorized financial advisor before any investment decision. Past observed outcomes do not predict future results.