Currency Risk Management for International Investors: Natural Hedges, Costs, and Practical Decisions

Every internationally diversified portfolio carries implicit currency risk. A GBP-based investor holding US equities, European bonds, or Japanese infrastructure funds is exposed to fluctuations in exchange rates that may substantially amplify or reduce investment returns in sterling terms. Deciding how to manage this exposure — whether to hedge, how much to hedge, and which asset classes most warrant protection — is an important but often neglected dimension of portfolio construction.

The Currency Effect on Investment Returns

Currency movements can be the dominant driver of returns for international investments in any given year. Consider a UK-based investor holding US equities in 2022: US equities (in USD) fell approximately 19% in 2022. However, sterling weakened significantly against the dollar in the same period, particularly during the Truss-Kwarteng mini-budget crisis of autumn 2022. For a sterling investor, the dollar strength partially offset the equity loss — the sterling return from US equities in 2022 was substantially less negative than the USD return.

The reverse holds in years when sterling strengthens: a UK investor's overseas equity returns are reduced in sterling terms when GBP appreciates relative to foreign currencies.

Over long periods, currency effects on equity returns tend to partially cancel out as exchange rates mean-revert. The empirical evidence suggests that currency is not a significant driver of long-run equity return differentials between markets over 10–20 year periods. However, over shorter periods and across fixed income holdings, currency movements can be decisive.

Natural Hedges: How Your Portfolio May Already Be Protected

Before deciding to pay for currency hedging, it is worth identifying natural hedges that may already exist in a client's balance sheet:

Foreign revenue from domestic companies: Large UK companies in the FTSE 100 derive approximately 70–75% of their revenues from outside the UK. A sterling investor holding FTSE 100 companies is not purely exposed to UK domestic economic conditions. The companies themselves have natural hedges through their foreign earnings streams.

Property in multiple currencies: An internationally mobile investor holding properties in the UAE (dirham, pegged to USD), Spain (euro), and the UK has a natural multi-currency balance sheet. The investment portfolio's currency composition should complement rather than duplicate this.

Liability currency matching: An investor who expects to spend significantly in euros (a home in Spain, children at European schools) has a natural interest in holding euro-denominated assets to match these liabilities. The hedge here is structural rather than financial.

Diversification as implicit hedging: A globally diversified portfolio that holds assets in many currencies is inherently less exposed to any single currency movement than a portfolio concentrated in one overseas currency. The currency risk of a 65% USD equity portfolio is very different from that of a portfolio spread across USD, EUR, JPY, GBP, CHF, and emerging market currencies.

When Currency Hedging Adds Most Value: Fixed Income

The case for currency hedging is far stronger for fixed income than for equities. The reason lies in the relative magnitude of returns.

For equities, long-run expected returns are 5–9% per year in real terms, depending on the market and period. Currency movements of 5–10% per year are meaningful but not dominant relative to equity returns over multi-year holding periods.

For investment-grade government bonds, expected returns are typically 2–5% per year in real terms in the current environment. A 10% adverse currency movement completely wipes out multiple years of bond returns. For a GBP-based investor holding US Treasuries or European government bonds, the currency risk of an unhedged position is typically larger than the underlying return expectation. Hedging is almost always appropriate for international fixed income holdings.

This distinction is widely acknowledged in institutional portfolio management. Most global bond funds and aggregate bond ETFs targeting non-domestic investors are available in currency-hedged share classes precisely because the economics strongly favour hedging for fixed income.

The Cost of Forward Hedging

Currency hedging is typically implemented using forward contracts or currency futures: agreements to sell a foreign currency and receive the domestic currency at a specified future date and rate. The cost of this hedge is determined by the interest rate differential between the two currencies.

The fundamental principle: the forward rate reflects the expected future spot rate under covered interest rate parity. If USD interest rates are higher than GBP rates (as has been the case for much of the post-2022 period), then forward USD is cheaper than spot USD — meaning a GBP investor hedging USD exposure receives a positive hedging carry (the hedge is "free" or even positive return). Conversely, if GBP rates are higher than the foreign currency rate, hedging costs money.

As of 2025–2026, USD interest rates have been higher than EUR and JPY rates for an extended period, making hedging from EUR or JPY back to USD relatively cheap or even positive carry, while hedging from USD back to GBP depends on the prevailing rate differential.

The cost of hedging is not static and needs to be reassessed periodically. A hedging strategy that is cost-positive or cost-neutral in one rate environment may be meaningfully expensive in another.

Hedged vs Unhedged: Equity Funds in Practice

For GBP-based investors in global equity funds, both hedged and unhedged versions of major ETFs are available. A comparison of the iShares Core MSCI World UCITS ETF (unhedged, GBP share class) against the currency-hedged GBP-hedged equivalent provides a concrete illustration.

Over periods when GBP has weakened against the USD (as in 2022), the unhedged version outperforms. Over periods when GBP has strengthened (or the USD has weakened), the hedged version outperforms. Neither version systematically outperforms over long periods — the currency effect averages out over time, while the hedging costs (when present) subtract slightly from the hedged version's return.

The practical recommendation for most long-term equity investors: hold unhedged global equity exposure. The costs of hedging (rolling monthly contracts, periodic mismatch) subtract from returns, while the long-run benefit is small. Exceptions exist for investors with very short time horizons, specific near-term currency requirements, or especially concentrated single-currency equity exposure (a US equity specialist portfolio entirely in USD may warrant partial hedging for a GBP investor).

Special Considerations for Internationally Mobile Investors

For globally mobile high-net-worth individuals — those who may retire in a different country, maintain homes in multiple jurisdictions, or spend significant time outside the UK — the currency hedging question is more complex than for a domestically focused investor.

Key considerations include:

Expenditure currency: An investor planning to retire in Spain should hold a meaningful proportion of their investment assets in euros, since their future spending stream is primarily euro-denominated. This is not a hedge but a natural currency matching strategy.

Domicile and tax residency changes: Currency exposures that are rational today may change significantly if the investor changes tax residency. A portfolio optimised for a GBP-based investor may need significant restructuring if the investor relocates to the UAE (USD-pegged), Switzerland (CHF), or Australia (AUD).

Multiple bank accounts in multiple currencies: Many internationally mobile investors maintain cash accounts in USD, EUR, and GBP as an operational hedge, allowing expenditures in each currency to be made from the appropriate account without forced currency conversion.

Offshore bonds and multi-currency portfolios: Offshore investment bonds issued by major life insurers can hold funds in multiple base currencies, providing structural multi-currency diversification within a single vehicle without the need for formal hedging.

Practical Implementation Framework

A simple framework for currency risk management decisions:

1. Map the currency composition of future spending requirements (near-term, medium-term, long-term).
2. Map the currency composition of the existing balance sheet (investment assets, property, cash).
3. Identify natural hedges within the balance sheet.
4. For any remaining material currency mismatches:
   • For fixed income assets: consider formal hedging (hedged share class ETFs or forward contracts).
   • For equity assets with long-term horizons: generally hold unhedged; reassess if single-currency concentration is extreme.
   • For near-term spending requirements in a foreign currency: match with assets denominated in that currency.

Compliance and Regulatory Note

Currency hedging involves derivative instruments that carry counterparty risk and can result in losses if used inappropriately. The cost of hedging changes with interest rate differentials and should be evaluated periodically. Currency movements can be unpredictable and substantial. This article is for general information only and does not constitute personal financial advice. You should seek qualified professional advice before making decisions about currency risk management within your portfolio.

How Global Investments Can Help

Currency risk management is an area where the complexity of internationally mobile investors' situations requires bespoke analysis rather than off-the-shelf solutions. At Global Investments, we map each client's full multi-currency balance sheet — investments, property, pension entitlements, expected future expenditure — before making currency allocation and hedging recommendations. Our clients span markets around the world and multiple currency zones, and we bring direct experience of the practical decisions that globally mobile investors face. Please contact our team to discuss your currency risk exposure and how it might be managed within your broader wealth strategy.