Multi-Currency Investing: Managing Currency Risk Across International Portfolios

For internationally mobile investors, currency is not a peripheral concern — it is central to portfolio construction. A UK investor holding US equities may see their dollar-denominated portfolio rise by 10% in a year, only to find the return in sterling terms is closer to 3% after a strengthening pound. Conversely, sterling weakness can amplify foreign asset returns, turning a modest local gain into an excellent outcome in home-currency terms.

Managing this currency dimension — understanding exposure, deciding when to hedge and when to embrace it, and choosing the right custodians — is one of the most important skills for the international investor.

Understanding Currency Exposure

Currency exposure arises whenever you hold an asset denominated in a currency other than your "base" currency (typically the currency of your primary expenditure or future liabilities).

Direct exposure is straightforward: holding US dollars in a bank account or US Treasury bills gives you direct USD exposure. If the dollar weakens against sterling, the sterling value of your holding falls.

Indirect exposure is more subtle. A UK company that earns 60% of its revenues in dollars has embedded USD exposure in its equity. A property fund holding Miami real estate has USD exposure. Even a "global equity fund" hedged to sterling may have residual currency exposure through companies' underlying operational currencies.

Measuring exposure: a simple approach is to identify the currency denomination of each asset in your portfolio and express each as a percentage of total portfolio value. A more sophisticated approach analyses the revenue and cost structure of equity holdings to identify operational currency exposure beyond the denominated currency.

Currency Risk: Friend or Enemy?

Currency volatility is often framed purely as a risk to be managed. The reality is more nuanced:

Diversification benefit: currencies do not all move together. Holding a basket of currencies reduces the volatility of the overall portfolio versus a single-currency approach. Over long periods, currency movements can add diversification that partially offsets equity and bond risk.

Real return dimension: if a currency depreciates because its home country has higher inflation, that depreciation may reflect an underlying real-return problem rather than pure currency noise. Investing in high-quality currencies (those backed by strong institutions, rule of law, and prudent fiscal policy) tends to protect real purchasing power.

Hedging costs: hedging a currency exposure is not free. The cost reflects the interest rate differential between the two currencies. When UK interest rates are materially above US rates, hedging USD exposure back to GBP is cheaper than vice versa. As of 2026, with rates broadly similar across the G10, hedging costs are more moderate than in some periods.

Natural Hedging

Natural hedging involves matching currency exposures across assets and liabilities without using financial instruments.

Examples:

• An investor who plans to retire in Spain holds euro-denominated assets, naturally matching the currency of future living costs
• A business owner with USD revenues holds USD assets, matching the income stream
• An investor with a Swiss franc mortgage against a Swiss property — the debt and asset are denominated in the same currency

Natural hedging is elegant but requires discipline in portfolio construction. It works best when future liabilities are reasonably predictable in currency terms.

Which Currencies Should You Hold?

There is no universal answer, but several frameworks help:

Match your liabilities. If you will retire in Europe, hold euros. If your children's school fees are in dollars, hold dollars. Liability-matching is the most robust justification for any currency allocation.

Diversify across reserve currencies. The US dollar, euro, Swiss franc, and Japanese yen have historically been the "safe haven" currencies that strengthen in times of stress. Holding a blend provides resilience against stress in any one currency area.

Avoid concentrated exposure in small or emerging market currencies. Unless you have specific expertise or a liability-matching reason, large positions in currencies with limited liquidity or weaker institutional backdrops add risk disproportionate to potential return.

Consider the commodity dimension. The Australian dollar, Canadian dollar, and Norwegian krone are commodity-linked currencies. They tend to perform well when commodity prices rise, providing a partial hedge for investors with inflation-exposed liabilities.

FX Overlay Strategies

An FX overlay is a hedging strategy applied on top of an existing portfolio to manage currency exposure without changing the underlying investments. Common approaches:

Forward contracts: lock in a future exchange rate for a defined period. A UK investor holding $500,000 of US equities might enter a three-month forward to sell USD/buy GBP at today's rate, eliminating currency risk for the period. Forwards roll forward on expiry — continuous rolling is the standard approach for ongoing hedging.

Currency options: provide protection against adverse currency moves while retaining the ability to benefit from favourable moves. More expensive than forwards but offer asymmetric payoff.

Passive hedging: many international fund managers offer GBP-hedged share classes that systematically hedge currency exposure back to sterling. These are the simplest implementation for fund-based portfolios.

Dynamic hedging: adjusting hedge ratios based on currency valuation or momentum signals. This requires active management and is typically the domain of specialist currency managers.

Who should hedge? Hedging is most important for:

• Short-term investors where currency movements could dominate returns over the investment horizon
• Investors with defined sterling liabilities (retirement at a fixed date, school fees, etc.)
• Large single-currency concentrations where the currency risk is disproportionate to the investment thesis

Long-term investors with diversified global portfolios often find that currency effects average out over time, and the cost of systematic hedging outweighs the benefit.

Practical Custody and Brokerage Options for UK Expats

The practical implementation of multi-currency investing depends heavily on where you hold your assets.

UK brokers and platforms: most UK-based platforms (Hargreaves Lansdown, Interactive Investor, AJ Bell) allow investment in overseas securities but typically convert the underlying currency exposure back to sterling at each transaction, rather than maintaining multi-currency account structures. This is functional but not ideal for investors who wish to manage FX timing actively.

Interactive Brokers is widely used by internationally mobile investors and HNW individuals. It offers genuine multi-currency account functionality — you can hold cash in 20+ currencies, execute FX transactions at competitive rates, and buy securities in their local currency. The platform is sophisticated; the fee structure is competitive for active investors.

Offshore investment platforms (such as those offered by Quilter International, Utmost International, or Zurich International) hold assets in wrap structures that can accommodate multi-currency portfolios. These are often used within offshore bond wrappers for tax efficiency.

Private banks — particularly those with international operations such as HSBC Private Banking, Standard Chartered Private Bank, Pictet, or Lombard Odier — offer the most sophisticated multi-currency functionality, including discretionary management with explicit currency mandates. Minimum investment levels typically start at £1–5 million.

Multi-currency banking: banks including Monzo (limited), Revolut, Wise, and Starling offer multi-currency accounts for day-to-day spending. These are not investment custody solutions but are useful for managing living expenses across currencies.

Tax Considerations for UK Investors

Currency gains and losses have tax implications that are often overlooked:

CGT on currency gains: the position differs by asset type. Foreign currency held in a personal bank account is exempt from CGT for individuals, trustees and personal representatives — foreign currency bank accounts were taken out of the scope of CGT from 6 April 2012, so simply holding and converting currency in a bank account does not create a chargeable gain. However, gains arising from currency movements on other non-sterling assets (for example, directly held foreign securities, or currency futures and options, which are specifically outside the bank-account exemption) can still be subject to CGT for UK residents, with the gain or loss measured in sterling terms. Currency exposure embedded in pooled funds is taxed under the rules for the fund holding itself.

Hedging instruments: gains and losses on forward contracts and options used to hedge are generally treated as capital in nature if the underlying exposure is a capital asset.

Offshore bond wrappers: gains roll up within the bond without CGT until withdrawal, making them a useful structure for managing the tax complexity of multi-currency investing.

Building a Multi-Currency Framework

A practical approach for a HNW internationally mobile investor:

1. Identify your base currency — the currency of primary future expenditure (retirement income, property, family costs)
2. Map current exposures — list all assets and their currency denomination; note any indirect exposures through equities or funds
3. Identify significant mismatches — large positions in currencies with no corresponding liability are uncompensated exposures
4. Set a hedging policy — decide which exposures to hedge (typically large, short-term-relevant mismatches) and which to leave open (diversification, long-term holdings)
5. Choose custodians — ensure your investment platform can accommodate multi-currency holding and FX transactions at sensible rates
6. Review annually — currency policy should be revisited as life circumstances, market conditions, and interest rate differentials change

How Global Investments Can Help

Global Investments specialises in building and managing international portfolios for clients across multiple currencies and jurisdictions. We advise on currency policy within portfolio mandates, facilitate access to multi-currency custody solutions, and integrate currency management with broader tax planning — particularly for clients moving between countries where the relevant base currency may change.

Currency values fluctuate and exchange rate movements can adversely affect the value of your investments. Hedging strategies can reduce but not eliminate currency risk and involve costs. This article is for general information only and does not constitute financial advice. Tax rules may vary depending on individual circumstances.