What Moves Exchange Rates? Interest Rates, Inflation, Growth and Expectations

USD/JPY is a dollar price and a relative yen price

A USD/JPY quote of 150 means one US dollar is expressed as 150 Japanese yen. A higher quote is dollar appreciation and yen depreciation in that quotation convention; a lower quote is the reverse. The cause, however, cannot be reduced to “the dollar was strong.” The ratio may change because of a US development, a Japanese development, a global factor affecting both, or an imbalance between orders at that moment.

The Bank of Japan’s educational material defines an exchange rate as the exchange ratio between a foreign currency and the home currency. That gives us a practical rule: compare the euro area and the United States for EUR/USD, or the United Kingdom and Japan for GBP/JPY, using the same variables and as-of date. Selecting one favourable statistic on one side while ignoring a larger change on the other produces an explanation that is easy to fit after the event and difficult to test.

Sort the story into six connected boxes

The boxes overlap. An oil-price move, for example, can affect inflation, terms of trade, company income, fiscal balances and risk appetite together.

Japan’s Financial Services Agency lists national interest rates, economic conditions and indicators, monetary policy, politics and official remarks among the factors that can move foreign-exchange rates. The goal is not to accumulate an endless list. Attach three fields to each candidate driver: which side of the pair it concerns, the horizon over which it could matter, and what the market appeared to expect before the observation.

Compare the expected path, not just today’s policy rate

All else equal, a higher available return can make assets in a currency more attractive. All else is rarely equal. A high yield may compensate for high inflation, credit concerns or scarce liquidity; hedging costs and currency movement can exceed the yield. “The higher-rate currency must appreciate” is therefore not a reliable law.

At a policy meeting, record more than the rate decision: the statement, projections, press conference, vote split and balance-sheet guidance can all affect the expected path. A hold can still push expectations later if officials challenge an early-cut assumption. A hike can have a muted or opposite observed reaction if it was fully anticipated and communication reduces expectations for what follows. These are possible mechanisms, not directional rules.

Begin with primary material: the Bank of Japan’s Monetary Policy Meetings, the Federal Reserve’s FOMC pages and the ECB’s policy decisions. A fast headline can be useful for discovery, but the decision document, reference period and publication time are what make a research record reproducible.

Markets reassess expectations, not labels such as "good" or "bad"

Read a release as a row containing actual, consensus, previous, revised previous and material components. Consensus is not an official statistic; vendors can use different panels and cut-off times, so record its source. An actual can improve from the prior period yet miss consensus. A soft headline can coexist with a firm component that policymakers currently emphasise.

Then ask what positioning existed before the number, whether another release arrived at the same second, and which part of the report the central bank has highlighted. The companion forex economic calendar guide shows how to keep actual, consensus, previous and revision in separate fields rather than compressing the event into one colour.

Why price can move without a new macro headline

Export and import settlement, institutional currency hedges, allocations into bonds or equities, option hedging and the forced closure of speculative positions all create currency demand. If many participants already hold the same exposure, a seemingly supportive release can coincide with profit taking or an unwind. Since no outside observer sees every order across a fragmented OTC market, a responsible explanation states what the available data cannot reveal.

In thin conditions or around important news, a relatively small executable order can move through several price levels while spreads widen. A large range is not automatically proof that the fundamental news was exceptionally strong. Venue volume and order-book data can be useful, but each covers only its defined market; preserve the venue, instrument and timestamp with the observation.

Official intervention is another direct source of demand or supply. In Japan, the Bank of Japan explains that the Minister of Finance has authority over intervention and the BOJ acts as agent. That institutional fact does not allow a trader to predict whether, when or with what durable effect an intervention will occur. Use official Ministry of Finance and BOJ disclosures for verification after publication.

The same upside surprise, two different observed reactions

Every number and reaction below is invented to practise avoiding a deterministic rule. It does not represent a real country, release or currency and does not forecast how a future inflation report will trade.

All values and returns are fictional. The comparison shows only that revision, prior pricing, concurrent news, positions and liquidity can accompany different outcomes.

The lesson is not to fade releases or to ignore data. It is to write the hypothesis and its falsification condition before publication, then record the statistic, revision and price response as separate observations. Choosing the convenient explanation after seeing the move creates a narrative that cannot be reused or honestly tested.

Eight checks when a currency headline appears

1. Identify the base and quote currencies and state what a higher or lower quote means.
2. Compare both economies using the same variable, frequency and as-of date.
3. Verify publication time, reference period, units, seasonal adjustment and revision policy at the primary source.
4. Keep actual, consensus, prior, revision and important components in separate fields.
5. Frame the hypothesis around a change in the expected policy path, not only the current rate.
6. Retain alternative explanations involving trade, hedging, positioning and liquidity.
7. Predefine the horizon and what evidence would invalidate the hypothesis.
8. Save the source, timestamp and observed response without turning the response into a forecast.

Use the Macro Research Workbench to organise selected public data such as COT, rates and real yields descriptively. The Macro Analysis Guide explains the wider source, date, transformation and validation workflow. The workbench is not a real-time news feed and does not give trade direction or price forecasts.