What actually moves exchange rates

An exchange rate is just a price: what one currency costs in terms of another. Like any price, it moves when supply and demand change. What makes currencies interesting is how many different forces feed into that supply and demand, and how quickly the market reacts to each of them. Here are the big ones.

Interest rates

If there's one force that matters most in the short and medium term, it's interest rates. When a country's central bank raises rates, holding that currency pays more, so investors around the world want more of it, and it tends to strengthen. When rates fall, the reverse happens.

What matters is usually the difference between two countries' rates rather than either rate alone. That's why USD/JPY moved so much during the period when US rates rose while Japan's stayed near zero. It's also why currency markets react so strongly to central bank meetings and even to hints in speeches about what might happen next. Markets move on expectations, often before a rate change actually happens.

Inflation

Over longer periods, inflation matters a great deal. If prices in one country rise much faster than in another, each unit of its currency buys less, and over time the exchange rate tends to adjust to reflect that. Countries with persistently high inflation, such as Argentina and Türkiye in recent years, have seen their currencies lose a large share of their value against the dollar.

This idea is called purchasing power parity. It's a poor guide to where a rate will be next week, but a useful guide to why a currency has drifted in one direction over a decade.

Trade and commodities

Countries that export more than they import tend to see steady demand for their currency, because foreign buyers need it to pay for those exports. For countries that rely heavily on a single commodity, its price can dominate: the Canadian dollar and Norwegian krone often move with oil, the Chilean peso with copper, and the Australian dollar with iron ore.

Risk appetite and safe havens

When investors are feeling confident, money flows into higher-yielding and emerging-market currencies. When fear takes over, it flows into perceived safe havens, traditionally the US dollar, the Japanese yen, and the Swiss franc. This is why so many currencies can fall at the same time during a global shock, even ones with little direct connection to it.

Politics and economic news

Elections, budgets, and political uncertainty can move a currency sharply, particularly when they raise questions about government finances or central bank independence. Regular data releases matter too: employment figures, inflation reports, and growth numbers all change what the market expects central banks to do next.

Central bank intervention and pegs

Some central banks step directly into the market to buy or sell their own currency, either to slow a sharp move or to defend a fixed rate. Countries with currency pegs do this constantly, which is why their rates barely move.

What this means for you

Nobody reliably predicts short-term currency moves, including professional traders. If you have a large, unavoidable conversion coming up, such as tuition, a property payment, or a big trip, the practical approach is to watch the rate for a while with the currency converter, decide what rate you'd be happy with, and consider splitting the conversion into a few chunks over time rather than trying to time a single perfect moment. And remember that the fees and markup your provider charges often matter more than a small move in the market rate.