Currency Risk

Currency risk — also called foreign exchange risk or FX risk — is the exposure of an investment portfolio to losses from unfavourable changes in exchange rates between currencies. When you invest in a bond denominated in euros or a stock trading in yen, you bear both the asset’s own market risk and the risk that your currency falls against the euro or yen, eroding returns.

How currency risk works

Suppose you are a US investor and you buy a German bond with a 3% coupon, denominated in euros. The bond is safe — Germany has low credit-risk. But you earn that 3% coupon in euros, and you are paid back in euros. What happens if the euro weakens?

Example: You invest $100,000, getting 100,000 euros at an exchange rate of 1 EUR = $1.00. The bond pays 3% annually. After one year, you receive 3,000 euros of interest. In dollar terms, if the euro has not moved, that is $3,000 of return — a 3% gain.

But if the euro has weakened to 1 EUR = $0.95 by the end of the year, those 3,000 euros are worth only $2,850. Your dollar return is 2.85%, not 3%. The 0.15% difference is due to currency risk. If the euro had strengthened to 1.05, your return would have been 3.15%.

Over a full year, currency moves can be volatile. The euro might swing 10% or more against the dollar. If a foreign asset returns 5% but the currency loses 10%, you lose 5% overall (roughly).

Currency risk for international investors

For a US-based investor, any investment outside the US carries currency risk unless it is explicitly hedged. The same is true for investors in Japan, Britain, Australia, or any home currency.

The magnitude is substantial. Consider the returns on international equities:

• The stock itself generates returns (price appreciation plus dividends).
• The currency generates additional returns (or losses) from appreciation or depreciation.

Over decades, the currency effect averages close to zero for major currencies (they do not trend one way forever). But over shorter periods, 1-5 years, currency effects can be the dominant driver of international returns.

For instance, a Japanese stock might be up 20% in yen, but if the yen has fallen 15% against the dollar, the US investor sees a return of only about 2% in dollars. Currency risk is not theoretical; it is felt by every international investor.

What drives currency movements

Currency risk is driven by:

• Interest rate differentials. If US interest rates are 5% and German rates are 2%, the dollar tends to strengthen (investors want to earn the higher US rate). Currency markets price in these differences.

• Inflation differentials. Higher inflation in one country erodes its currency’s purchasing power, pushing it lower.

• Economic growth. Faster growth in one country attracts investment and strengthens its currency.

• Risk sentiment. During crises, investors flee to safe currencies (historically the dollar, yen, or Swiss franc), regardless of interest rates.

• Geopolitical shocks. War, sanctions, or political instability can cause sharp currency swings.

• Central bank policy. Surprise interest rate moves or explicit currency intervention can move rates.

Unlike market-risk, which is broadly consistent across investors, currency risk is relative. Currency risk for a US investor is not currency risk for a European investor — it is currency benefit. If you are based in Germany, investing in US dollar assets exposes you to dollar-euro risk, not euro risk.

Hedging currency risk

For investors who do not want currency risk, it can be hedged using forwards, futures, or options. A forward contract locks in an exchange rate for a future date. If you invest in German bonds and buy a euro/dollar forward contract that locks in the current rate, you eliminate currency risk — you will receive a known dollar amount.

Hedging has costs: the forward rate typically differs from the spot rate, reflecting interest rate differentials. But for investors who want predictable returns in their home currency, hedging is available and common.

Many international index funds and ETFs come in both hedged and unhedged versions. The unhedged version carries currency risk; the hedged version does not (but incurs hedging costs).

See also