What moves currencies?

When you buy EUR/USD, you're betting the euro will strengthen against the dollar. But why would a currency gain value in the first place? Technical analysis tells you when price moves. Fundamental analysis explains why. In this lesson, we lay out the full map of the forces that push a currency up or down.

Keep one simple idea in mind: the price of a currency is the price of demand for a country's assets. If investors around the world want to buy US Treasuries, they first have to buy dollars. The stronger that demand, the higher the dollar goes.

1. Interest rates: the number one driver

Money goes where it earns the most. When a central bank raises rates, holding assets in its currency pays more, and capital pours in. A rate cut does the opposite and makes the currency less attractive. That's why traders hang on every word central bankers say.

What matters isn't one country's rate on its own, but the gap between two countries. This is called the interest rate differential. A pair like USD/JPY is highly sensitive to the spread between US and Japanese yields: when that spread widens in favour of the US, the pair tends to rise.

2. Growth and inflation

A fast-growing economy attracts investors: companies earn more, stocks rise and capital flows in. Solid growth also pushes the central bank to keep rates high, which supports the currency.

Inflation cuts both ways. In the short term, inflation that comes in hotter than expected often lifts the currency, because the market prices in a rate hike to fight it. Over the long run, persistently high inflation erodes the currency's purchasing power and weakens it. So everything depends on how the central bank is expected to react.

3. Capital flows and the trade balance

A country that exports a lot receives payments in foreign currencies, which its companies convert back into the local one: that's natural demand for its currency. A country running a chronic trade deficit, on the other hand, has to attract foreign capital to fund it.

Financial flows now weigh far more than trade in goods. Forex turns over about $7.5 trillion a day (BIS, 2022), an amount that dwarfs global trade in goods. Purchases of stocks and bonds, cross-border takeovers and sovereign wealth fund investments do most of the work.

4. Political risk and safe havens

Investors hate uncertainty. Tight elections, budget crises, geopolitical tension: when a country's future gets blurry, capital leaves and the currency falls. The British pound, for example, has been hit by sharp swings around major UK political events.

On a global scale, fear triggers a specific move: the flight to quality. When markets panic, money rushes into a handful of currencies seen as safe, mainly the US dollar, the Japanese yen and the Swiss franc, as well as gold. These assets can rise even when the bad news comes from their own country.

5. Expectations versus reality

Here's the trap almost every beginner falls into. Good news doesn't necessarily push a currency higher. The market lives in the future: prices already reflect what participants expect. What moves the price is the surprise, the gap between what was expected and what actually happens.

Hence the old saying buy the rumor, sell the news. If everyone is sure a central bank will hike, buyers position themselves for weeks. On the day, the hike lands, but the currency drops: those who bought take profits and there are no new buyers left.

How to combine these drivers

All these forces act at the same time, sometimes in opposite directions. A currency can benefit from high rates while suffering from a political crisis. The fundamental trader's job isn't to find the right factor, but to spot the one dominating the market at a given moment. In some periods, everything revolves around inflation; in others, only fear matters.

1. Identify the dominant theme of the moment (rates, inflation, growth, fear).
2. Compare the two economies in the pair: which one is stronger on that theme?
3. Check what the market already expects before each release.
4. Use technical analysis to pick your entry and your stop.

In the next lessons, we break down each driver: central banks, inflation, jobs, growth, and then how to prepare your week with the economic calendar.