Know your true return
on foreign shares

The Hidden Layer of Every Foreign Investment

When investors buy shares listed on a foreign exchange, they are making two simultaneous bets: one on the performance of the company, and one on the relative strength of the foreign currency against their home currency. Most investors focus almost entirely on the first and give the second little thought — until the currency move wipes out their gains.

Exchange rates between major currency pairs routinely move 5–15% in a single year. In a year where the AUD/USD rate shifts from 0.70 to 0.65, an Australian investor holding US shares has effectively received a 7% bonus on their return even before the share moves at all. The same logic works in reverse: a strengthening home currency quietly erodes the value of foreign holdings.

A Concrete Example

Suppose you buy 100 shares of a US company at USD 50.00 each, when the AUD/USD exchange rate is 0.70. Your total outlay in Australian dollars is:

• Cost in USD: 100 × $50 = $5,000
• Cost in AUD: $5,000 ÷ 0.70 = $7,143

One year later, the share price has risen to USD 58.00 — a solid 16% gain. But the AUD has also strengthened to 0.76. Your position is now worth:

• Value in USD: 100 × $58 = $5,800
• Value in AUD: $5,800 ÷ 0.76 = $7,632

Your actual AUD gain is $489, or about 6.8% — not 16%. The 7.6% appreciation of the AUD consumed most of your share market gains.

The Two Forces Work Together — and Against Each Other

There are four possible scenarios for a foreign share investment:

• Share rises, foreign currency strengthens: Best case — both forces work in your favour.
• Share rises, foreign currency weakens: Partial offset — gains diluted by FX headwind.
• Share falls, foreign currency strengthens: Partial offset — FX tailwind cushions the loss.
• Share falls, foreign currency weakens: Worst case — losses compounded by both forces.

Why Most Investors Underestimate FX Risk

Brokerage statements typically show your position value converted to your home currency at the current rate, but they rarely break down how much of your gain or loss came from the share itself versus the currency. Share selection risk is addressed through research and diversification. Currency risk can be addressed through hedging, choice of hedged ETFs, or simply being conscious of your exposure when sizing positions.

How Exchange Rates Are Quoted

An exchange rate expresses the value of one currency in terms of another. AUD/USD = 0.6500 means one Australian dollar buys 0.65 US dollars. The first currency in the pair is called the base currency; the second is the quote currency.

Rates are quoted as a two-sided market: a bid (the rate at which you can sell the base currency) and an ask (the rate at which you can buy it). The difference is the spread — how brokers make money on each transaction. Retail investors always get the worse side of the spread.

Spot vs. Settlement

The spot rate is the current market rate for immediate delivery of a currency. When you buy foreign shares through a brokerage, your broker converts your home currency at their own rate — which may be the spot rate plus a margin, a flat conversion fee, or both. This cost often goes unnoticed but compounds over many transactions.

Cross-Rates: When Your Pair Isn't Directly Quoted

Major pairs like AUD/USD and GBP/USD are traded directly in liquid markets. If you want AUD/JPY, it is typically derived by crossing AUD/USD and USD/JPY — hence the term cross-rate. Cross-rates tend to have slightly wider spreads and can behave unpredictably when both underlying pairs move simultaneously.

Why the Rate You Get Differs From What You See

• Broker FX margin: Most brokers add 0.3–1.5% to the mid-market rate.
• Timing: The rate when your order was placed may differ from the rate when it settled.
• Transaction fees: Some brokers charge a flat conversion fee on top of the spread.

The ATO's Position on Foreign Currency

In Australia, foreign currency is treated as a separate asset class under the forex rules in Division 775 of the Income Tax Assessment Act 1997. When you buy foreign shares, the ATO views you as having made two separate transactions: acquiring shares, and acquiring foreign currency to pay for them.

When you sell your shares and convert the proceeds back to Australian dollars, any gain or loss attributable to exchange rate movement is a foreign currency gain or loss — distinct from your capital gain or loss on the shares themselves.

The $250,000 Threshold

The ATO provides a concession for individual investors: if your total foreign currency transactions are less than AUD 250,000 in a given income year, you may be eligible to disregard forex gains and losses, effectively rolling your currency exposure into the cost base of the shares. For most retail investors, this simplifies their tax position considerably.

Above the Threshold: Separate Reporting

• Forex gains are assessed as ordinary income, not capital gains — meaning no 50% CGT discount applies.
• Forex losses are generally deductible against ordinary income.
• Dividends received in foreign currency also create a forex calculation at the time of receipt.

Record-Keeping Is Critical

For every foreign share transaction record: date of purchase and sale, number of shares, price in foreign currency, the exchange rate on both dates, AUD cost and proceeds, and all fees.

What "Currency Exposure" Actually Means

When you hold foreign shares directly or through an unhedged fund, you have full currency exposure: every rise or fall in the foreign currency directly affects your home-currency return. A currency hedge neutralises this effect using forward contracts or swaps, giving you approximately the pure share market return regardless of exchange rate movements.

The Case for Unhedged Exposure

• Diversification: When domestic markets fall, the home currency typically falls too — boosting the value of foreign holdings and acting as a natural buffer.
• Cost: Hedging typically costs 0.2–0.5% per year depending on the interest rate differential. This compounds significantly over decades.
• Long-term mean reversion: Currency movements tend to smooth out for patient investors over long periods.

The Case for Hedged Exposure

Hedging makes most sense when you have a shorter investment horizon, need predictable cash flows in retirement, or want to isolate stock market returns from currency noise when evaluating performance.

Direct Shares: Accepting Full Currency Exposure

For investors who hold individual foreign shares directly, formal hedging is expensive and impractical at small portfolio sizes. Direct share investors generally accept full currency exposure as part of the package — which makes understanding your realised home-currency return all the more important.

Mistake 1: Using the Wrong Exchange Rate

Many investors calculate returns using the current mid-market rate from Google or a finance site — not the rate they actually paid. Even a 1% error can substantially distort your calculated P&L on large positions. Always use the actual rate from your trade confirmation.

Mistake 2: Ignoring the True Cost of Currency Conversion

Brokerage commissions are visible; currency conversion costs are often buried. Most brokers add 0.5–1.5% to the exchange rate on both buy and sell sides. On a round trip this can total 1–3% of the trade value — often more than the brokerage commission itself.

Mistake 3: Measuring Performance in the Wrong Currency

Tracking foreign shares in the foreign currency feels natural, but your wealth is denominated in your home currency. A 15% gain in USD is not a 15% gain in your purchasing power if the USD has weakened against your home currency by 10%. Always evaluate investment performance in your home currency.

Mistake 4: Misunderstanding the Break-Even Point

If a share returns to its purchase price, many investors assume they break even. This is only true if the exchange rate is also unchanged. If the foreign currency has weakened since purchase, the share price needs to rise above the original purchase price just to return to zero in home-currency terms.

Mistake 5: Treating Unrealised Gains as Certain

An unrealised gain on a foreign share position is denominated in a foreign currency. Until you sell and convert, that gain is exposed to currency risk. A position showing a strong paper profit can see a significant portion evaporate if the exchange rate moves unfavourably before you act.

P&L Calculation as a Decision Tool

Accurate P&L calculation — particularly when it separates share performance from currency performance — is a powerful forward-looking decision tool, not just an accounting exercise. Knowing where your gain or loss is coming from lets you answer the questions that should drive your actions.

Is My Return What I Think It Is?

Investors routinely overestimate or underestimate their returns because they track share prices in the foreign currency. Running the actual numbers — including your entry rate and current rate — often produces a different result than expected. This is the most basic and most commonly skipped step.

Where Is My Risk Coming From?

If your position is profitable primarily because of FX movement rather than share price appreciation, that changes the nature of the risk going forward. Currency gains can reverse quickly without any change in the underlying business. Breaking your return into its two components answers this question directly.

What Is My Home-Currency Break-Even?

For a losing position, your home-currency break-even is more useful than the foreign-currency break-even. It changes every time the exchange rate moves. At today's rate, you need to know: at what share price do I return to zero in my home currency?

How Does a Currency Move Change My Outcome?

Scenario modelling lets you quantify rather than guess. If your home currency weakens 5% with the share price unchanged, what does your P&L look like? This sensitivity analysis helps you understand the full range of outcomes and plan accordingly.