What Determines Exchange Rates? 8 Forces That Move Currencies

Exchange rates affect the price of your vacation, the cost of imported goods, the returns on international investments and even job prospects in export industries. Yet the reasons currencies move can seem mysterious. Here are the eight main forces behind exchange rates, explained in plain English.

See today’s numbers on our exchange rates page.

What is an exchange rate?

An exchange rate is the price of one currency in terms of another. If EUR/USD is 1.10, one euro costs 1.10 US dollars. When that number rises, the euro is strengthening against the dollar.

Floating vs fixed exchange rates

• Floating: the rate is set by supply and demand in the market. The US dollar, euro, British pound and Japanese yen all float.
• Fixed (pegged): a country ties its currency to another currency or basket and uses reserves to defend that level.
• Managed float: the currency floats, but the central bank intervenes to smooth excessive volatility.

8 forces that move exchange rates

1. Interest rates

Capital flows toward higher returns. When a country’s interest rates rise relative to others, its currency can become more attractive and appreciate. What matters most is the real interest rate — the rate after inflation.

2. Inflation

Over the long run, currencies of high-inflation countries tend to lose value against those of low-inflation countries. This idea is captured by purchasing power parity (PPP): the same basket of goods should eventually cost about the same everywhere once converted at market exchange rates.

3. Trade and the current account

A country that imports more than it exports runs a current account deficit and needs steady inflows of foreign capital to finance it. If those inflows slow, its currency tends to weaken.

4. Central bank policy

Central banks such as the Federal Reserve, the European Central Bank and the Bank of England influence currencies through interest rate decisions, balance sheet policy and forward guidance. Some also intervene directly in currency markets.

5. Economic growth and data

Strong growth, employment and productivity data can boost a currency by attracting investment. Weaker-than-expected data often has the opposite effect.

6. Global risk sentiment

In times of stress, investors typically flee to “safe haven” currencies such as the US dollar, Swiss franc and Japanese yen. Emerging market and commodity-linked currencies often fall in these periods.

7. Politics and stability

Elections, policy uncertainty, rule of law and geopolitical events affect investor confidence. Stable, predictable institutions tend to support a currency over time.

8. Expectations and speculation

Currency markets are forward-looking. If traders expect a currency to weaken, selling can become self-reinforcing. The carry trade — borrowing in low-rate currencies to invest in high-rate ones — can amplify moves when it unwinds.

How currency moves affect you

• Travel: a stronger home currency makes trips abroad cheaper.
• Prices: a weaker currency raises the cost of imported goods and fuel.
• Investments: international stocks and bonds gain or lose value in your currency as exchange rates shift.
• Debt: borrowing in a foreign currency is risky if your income is in your home currency.

What this means for individual investors

1. Don’t try to time currencies. Even professionals struggle to forecast short-term moves.
2. Diversify internationally. Holding global assets spreads currency risk. See our guide to asset allocation and diversification.
3. Mind the costs of exchanging money. Compare the rate you’re offered to the mid-market rate using our currency converter.
4. Focus on real returns. Read how to protect your savings from inflation.

Conclusion

Exchange rates reflect a constant tug-of-war between interest rates, inflation, trade flows, central bank policy, growth, risk appetite, politics and market expectations. Understanding these forces won’t let you predict tomorrow’s rate, but it will help you interpret the headlines and build a plan that doesn’t depend on any single currency scenario.