FOUNDATIONS: COURSE 1 | LESSON 4

What moves currencies: rates, inflation, central banks

Learning objectives

By the end you can explain how interest-rate expectations drive currency demand — and why expectations is the key word.
By the end you can describe the chain from inflation data to central-bank decisions to exchange rates.
By the end you can interpret a currency pair's move as a two-sided story, not a one-currency event.

So far you've learned to place, size, and manage a trade. This course answers a more basic question you've politely postponed: why do these prices move at all? When EUR/USD rises from 1.0810 to 1.0870 over an afternoon, something changed in how thousands of banks, funds, and companies value euros against dollars. Most of the time, that something traces back to one family of forces: interest rates, the inflation that drives them, and the central banks that set them.

Interest rates: the gravity of the currency market

A currency is, among other things, something you can deposit and earn interest on. That makes relative interest rates the closest thing forex has to gravity.

Suppose US rates sit at 4.5% and eurozone rates at 2.5%. Large investors holding euros can sell them, buy dollars, and pick up an extra two percentage points of yield on the same cash. Done at scale — and it is done at enormous scale — that flow means selling EUR and buying USD, which pushes EUR/USD down. The general rule: money migrates towards higher yield, so a currency with rising rate expectations tends to strengthen, and one with falling rate expectations tends to weaken.

Note the honest hedging in "tends to". This is a dominant force, not a law of physics. Risk sentiment, politics, and positioning all interfere — occasionally for months. Anyone who tells you currencies always follow rates hasn't traded through a year when they didn't.

Expectations move prices, not announcements

Here's the twist that confuses every newcomer at least once. The European Central Bank cuts rates and… the euro rises. Broken market? No — you just watched the difference between news and new information.

Markets are forward-looking. If a cut was fully anticipated for weeks — signalled in speeches, priced into money markets — then by decision day, everyone who wanted to sell euros because of it already had. The announcement confirms old news. If anything moves the price, it's the surprise component: perhaps traders expected a cut plus hints of more cuts coming, and the ECB instead sounded cautious. Relative to expectations, that's hawkish — and the euro rallies on a rate cut.

Two pieces of trader vocabulary formalise this:

Hawkish = leaning towards higher rates or tighter policy → tends to support the currency.
Dovish = leaning towards lower rates or looser policy → tends to weigh on it.

And one rule worth engraving: markets move on the gap between what happened and what was expected. "Good" data with a downside surprise is bad news, and vice versa. This is why Lesson 2 (the economic calendar) will keep pointing you at the forecast column, not just the actual.

Inflation: the reason rates change

If rates are the gravity, inflation is what turns the dial. Most major central banks — the Federal Reserve (USD), the European Central Bank (EUR), the Bank of England (GBP), the Bank of Japan (JPY) — target inflation around 2%. The playbook:

Inflation runs hot (say CPI prints 4%): the central bank leans towards raising rates to cool spending and borrowing. Rising rate expectations → currency tends to strengthen.
Inflation runs cold or the economy weakens: the bank leans towards cutting to stimulate. Falling rate expectations → currency tends to weaken.

So a single inflation number can ripple through the whole chain. Worked example: US CPI is forecast at 2.8% year-on-year and prints at 3.4%. Traders instantly reprice the Fed — cuts get pushed later, maybe a hike creeps back into view. US yields tick up, the dollar strengthens, and EUR/USD drops from 1.0850 to 1.0795 in the hour after release. Nobody waited for the Fed to actually do anything; the expectation moved, so the price moved. That 55-pip move, by the way, is nearly twice the 30-pip stop from your Lesson F2.2 plan — a preview of why the economic calendar (next lesson) is a risk tool before it's an opportunity tool.

Central banks move markets outside the data, too. Scheduled decisions (the Fed meets roughly every six weeks), press conferences, meeting minutes, and even a deliberately vague speech from a central bank chair can reprice expectations. Traders parse this communication so obsessively that a single changed adjective in a statement can move a pair 40 pips.

Every pair is a tug-of-war

The last mental upgrade: a currency pair has two sides, and the price is the relative story. EUR/USD falling doesn't necessarily mean anything happened in Europe — it may be a pure dollar story. This is why on a day of strong US data you'll often see EUR/USD fall, GBP/USD fall, and USD/JPY rise together: one driver (the dollar), reflected in every pair containing it.

Practical habits this buys you:

Check both calendars. Trading EUR/USD means watching both eurozone and US events. A quiet Europe day means nothing if CPI lands in Washington.
Read moves correctly. If EUR/USD is flat, it might mean nothing happened — or that a hawkish ECB and strong US data pulled equally in opposite directions.
Don't over-attribute. "Euro up because of X" headlines are often written after the fact. Sometimes the honest answer is that the dollar side moved.

You don't need to become an economist to trade — plenty of successful traders lean mostly on charts. But even chart-first traders need this lesson's map, because the calendar events we cover next can steamroll any technical setup in seconds. Fundamentals set the weather; charts help you sail in it.

Key takeaways

Money migrates towards higher yield: rising rate expectations tend to strengthen a currency, falling ones weaken it — tendencies, not guarantees.
Prices move on the gap between outcome and expectation; a fully priced-in decision can produce no move, and a "paradoxical" one.
Hawkish = towards tighter policy (currency-supportive); dovish = towards looser (currency-negative).
Inflation is the dial that turns rates: hot CPI → rate-hike expectations → stronger currency, and the reverse.
Every pair is a two-sided tug-of-war — always ask whether a move is about the base currency, the quote currency, or both.