Investors building a diversified portfolio often consider including international stocks alongside domestic holdings, drawn by the potential benefits of exposure to different economies, industries, and growth trends around the world, seeking a broader opportunity set than any single domestic market alone can offer. Along with these potential benefits, international investing introduces an additional layer of complexity not present when investing solely within one’s own domestic market: currency risk. Understanding how currency movements can affect international investment returns is an important part of evaluating whether and how to incorporate international stocks into a broader investment strategy, rather than assuming that international returns behave identically to domestic returns once measured in one’s own home currency.
Currency risk, sometimes referred to as exchange rate risk, arises because an investor’s return on an international investment is influenced not only by how the underlying investment performs in its local currency, but also by how that local currency’s value changes relative to the investor’s own home currency over the holding period. Even if a foreign company’s stock performs well when measured in its own local currency, an investor whose home currency has strengthened significantly against that local currency during the same period may see a meaningfully smaller return, or even a loss, once the investment is converted back into their home currency terms, illustrating how two distinct forces, business performance and currency movement, combine to shape the final realized return.
How Currency Movements Translate Into Investment Returns
To understand this mechanic more concretely, consider an investor who purchases shares of a foreign company. If that company’s stock price rises by a certain percentage in its local currency over a given period, but that local currency simultaneously weakens against the investor’s home currency by a similar percentage, the investor’s actual return, once converted back to their home currency, could end up close to breakeven, despite the underlying investment technically performing well in its own local terms. Conversely, if the local currency strengthens against the investor’s home currency during the same period, the investor’s converted return could end up meaningfully higher than the local currency return alone would suggest.
This dynamic means that international investment returns, when measured in an investor’s home currency, reflect a combination of two separate factors: the performance of the underlying investment in its local market, and the movement of the relevant exchange rate over the holding period. These two factors can reinforce each other, offset each other, or move largely independently, depending on the specific circumstances involved.
Why Currency Movements Occur in the First Place
Exchange rates between currencies are influenced by a wide range of factors, including relative interest rate differences between countries, inflation trends, economic growth expectations, political stability, trade balances, and broader shifts in global investor sentiment toward risk. Because so many interacting variables influence currency movements, exchange rates can be notoriously difficult to predict with consistency, even for professional economists and currency specialists who dedicate significant resources to studying these relationships, a difficulty the SEC’s investor bulletin on foreign currency exchange trading also cautions individual participants about.
This inherent unpredictability is an important consideration for investors weighing international exposure, since it means currency movements introduce a layer of return variability that is largely separate from, and not necessarily correlated with, the fundamental business performance of the international companies being invested in.
Factors That Commonly Influence Currency Movements
- Differences in interest rates set by central banks in different countries.
- Relative inflation trends between countries.
- Overall economic growth expectations and investor sentiment toward a given country or region.
- Political stability and broader geopolitical developments.
Approaches to Managing Currency Risk
Investors and fund managers have developed several approaches to managing currency risk within internationally focused portfolios, an important consideration given that, as the SEC’s Investor Bulletin on international investing explains, changes in currency exchange rates can increase or reduce an investment’s return independent of how the underlying security performs in its home market. One common approach involves currency hedging, a technique that uses financial instruments specifically designed to offset the impact of currency movements, aiming to isolate the underlying investment return from the effect of exchange rate fluctuations. Some international investment funds are structured as currency-hedged products specifically for investors who want exposure to foreign companies without the added variability introduced by currency movements, effectively attempting to isolate the equity return from the currency return as closely as practically possible.
Other investors choose to leave their international exposure unhedged, accepting currency risk as a built-in feature of investing internationally, sometimes reasoning that over sufficiently long time horizons, currency effects may partially average out, or that unhedged currency exposure itself provides an additional, distinct source of diversification within a broader portfolio, separate from the diversification benefit of the underlying international stock exposure itself.
Weighing the Trade-Offs of Hedging
Currency hedging is not without its own costs and trade-offs. Hedging strategies typically involve additional costs, which can reduce net returns compared to an equivalent unhedged position, particularly during periods when currency movements would have otherwise worked in the investor’s favor. Additionally, hedging effectiveness can vary depending on the specific instruments and strategies used, meaning that a hedge may not always perfectly offset currency movements in practice, particularly during periods of unusual market volatility.
Because of these trade-offs, there is no universal answer as to whether hedged or unhedged international exposure is preferable for a given investor. The decision often depends on individual factors such as investment time horizon, overall risk tolerance, and the specific role international holdings are intended to play within the broader portfolio.
The Diversification Angle on Currency Exposure
Some investors and financial educators frame unhedged currency exposure not purely as an added risk, but also as a potential additional source of diversification within a broader portfolio, consistent with the SEC’s broader description of diversification as spreading investments across different holdings to help manage overall portfolio risk. Because currency movements are influenced by factors that do not always move in tandem with domestic stock market performance, unhedged international exposure can, in certain periods, behave somewhat differently from a purely domestic portfolio, potentially offering a modest diversification benefit distinct from the diversification already provided by exposure to different international companies and industries.
This diversification argument is not universally accepted among financial professionals, and views on the appropriate role of unhedged currency exposure within a portfolio vary considerably, which is part of why individual investors are encouraged to think through this question specifically in the context of their own broader portfolio construction and risk tolerance, rather than assuming a single universally correct approach applies to everyone.
Long-Term Historical Perspective on Currency Effects
Over sufficiently long historical periods, currency movements between major economies have shown a tendency to fluctuate within ranges rather than moving persistently and indefinitely in a single direction, though shorter and medium-term periods have certainly seen sustained, significant currency trends that meaningfully affected international investment returns during those specific periods. This historical pattern is sometimes cited as a reason why long-term investors may be somewhat less concerned about currency risk compared to investors with shorter time horizons, who have less time available for potential currency fluctuations to average out.
That said, historical patterns are not a guarantee of future currency behavior, and structural or policy changes in the global economic and financial system can influence currency relationships in ways that may not fully mirror historical patterns observed in the past.
Practical Steps for Thinking About International Exposure
For investors considering how to incorporate international stocks into their portfolio, a practical starting point involves clarifying the specific goals behind including international exposure in the first place, whether that is primarily about accessing growth opportunities in different economies, achieving broader diversification, or some combination of both. From there, investors can evaluate whether hedged or unhedged international investment options, or some blend of the two, best align with those specific goals and their overall comfort with the added variability that currency movements can introduce.
Reviewing the specific structure of any international fund being considered, including whether it uses currency hedging and what associated costs that hedging strategy involves, is a useful part of thorough due diligence before adding international exposure to a portfolio, rather than assuming all international investment options handle currency exposure in the same way.
Emerging Market Currencies Versus Developed Market Currencies
Currency risk is not uniform across all international markets. Currencies of developed economies with established central banks, deep capital markets, and long track records of relative monetary and political stability have historically tended to exhibit somewhat more measured fluctuations against one another compared to the currencies of certain emerging market economies, which can sometimes experience more pronounced volatility tied to factors such as political developments, commodity price swings, or shifts in global investor risk appetite. This does not mean emerging market currency movements are inherently unpredictable in a way that makes investment impossible, but it does mean that investors considering emerging market equity exposure often need to weigh a somewhat different, and at times more pronounced, currency risk profile compared to investing in developed international markets, a distinction consistent with the SEC’s observation that international investments can carry different levels of market liquidity and added exposure to political, economic, and social developments abroad.
This distinction is one reason many diversified international allocations are built with separate consideration given to developed and emerging market exposure, rather than treating all non-domestic markets as a single, uniform category carrying an identical currency risk profile.
How Currency Risk Interacts With Company-Level Fundamentals
It is worth noting that currency risk operates somewhat separately from the underlying fundamental performance of the specific companies being invested in. A well-managed, fundamentally strong international company can still deliver a disappointing return to a foreign investor purely due to unfavorable currency movements during the holding period, just as a fundamentally weaker company could deliver a surprisingly strong return to a foreign investor if currency movements happen to work in their favor during the same period.
This separation between company fundamentals and currency effects is an important distinction for investors to keep in mind when evaluating the performance of international holdings, since attributing a disappointing or surprisingly strong return entirely to company performance, without considering the currency component, can lead to an incomplete or potentially misleading understanding of what actually drove the realized investment outcome.
The Role of Multinational Companies in Blurring the Picture
Adding further nuance to this topic, many large companies, whether classified as domestic or international based on where they are headquartered, actually generate a significant share of their revenue from operations spanning multiple countries and currencies. This means that even a portfolio composed entirely of domestically headquartered companies may still carry meaningful indirect currency exposure, through the international revenue and operations of those companies, while a portfolio of internationally headquartered companies may have significant exposure back to an investor’s home currency through their own international operations.
Recognizing this blurred reality is a useful reminder that currency exposure within a portfolio is often more complex and layered than a simple domestic versus international classification might initially suggest, and that thoroughly understanding a portfolio’s true currency exposure sometimes requires looking beyond where a company happens to be headquartered.
A Balanced Way to Think About the Overall Trade-Off
Ultimately, currency risk is best understood not as a reason to avoid international investing altogether, but as one of several factors that deserves thoughtful consideration when deciding how much international exposure to hold and in what form. Just as investors weigh the trade-off between the growth potential and volatility of equities compared to the relative stability of fixed income, currency risk represents another dimension of trade-off specific to international investing, one that can add variability to returns in either direction depending on how exchange rates happen to move over a given period.
Approaching this trade-off with realistic expectations, rather than either dismissing currency risk entirely or treating it as a reason to avoid international diversification altogether, tends to support a more balanced and evidence-informed approach to building a globally diversified investment portfolio over time.
Conclusion
International stocks can offer valuable diversification and access to growth opportunities beyond an investor’s home market, but they also introduce currency risk as an additional, often underappreciated variable that can meaningfully influence realized investment returns. Understanding how currency movements interact with underlying investment performance, along with the available approaches for managing this risk through hedging or intentional unhedged exposure, equips investors to make more informed decisions about how international holdings fit within their broader, diversified investment strategy, rather than treating currency movements as an afterthought separate from the rest of their broader, ongoing portfolio planning and diversification process spanning multiple asset classes and regions.
This article is for educational and informational purposes only and is not personalized financial advice. Currency markets and international investments carry risk, so consult a licensed financial professional and read our full Financial Disclaimer before making financial decisions.
