Watching central banks together — Fed, ECB and BoJ

In the summer of 2022 the Federal Reserve was raising rates at a pace not seen in decades, while the Bank of Japan held them just below zero. That single disagreement between two central banks did more for USD/JPY than any chart pattern: the pair travelled from around 115 to nearly 150 in a little over a year. This is the heart of watching central banks as a system — not one decision, but the gap that opens up between them. In this article I will show how to follow the Fed, the ECB and the Bank of Japan together, and where to look for the trend.

Why policy divergence moves currencies

Over the medium term an exchange rate is driven above all by the relative path of two countries' monetary policy — the interest-rate differential between their currencies and, more importantly, the expected change in that differential. A single rate decision is just one point on that path. What matters is direction: whether a bank is hiking, holding or cutting, and how that looks next to the other bank in the pair.

When one central bank is tightening while another is easing, we call it monetary-policy divergence. Capital flows to where money earns more, so the currency of the bank raising rates tends to appreciate against the currency of the bank that is cutting — all else equal. The same mechanism underpins the carry trade, in which an investor borrows in a low-yielding currency to park capital in a higher-yielding one and earn the rate differential itself.

The key word is "expected". The market does not wait for the actual decision — it prices it in advance through interest-rate futures. So a pair reacts not to the fact that a bank raised rates, but to the bank signalling a faster or slower pace than assumed. A divergence that is only beginning to take shape in policymakers' rhetoric can move a rate long before the first real hike.

Which banks actually matter

A handful of central banks look after the major currencies, and their calendar is enough to cover most of the market. Four of them account for the currency core; two more add important secondary pairs:

• The Federal Reserve (Fed) — responsible for the US dollar, the world's most important currency. Its decisions are the reference point for all the rest, because the dollar sits on one side of most trades. I unpack the mechanics of a single meeting in a piece on how the Fed decision moves the dollar.
• The European Central Bank (ECB) — runs policy for the euro, the second most liquid currency. EUR/USD is the direct duel between the Fed and the ECB and the most heavily traded instrument on the market. What the Governing Council actually decides I describe in an article on the ECB decision and its impact on the euro.
• The Bank of Japan (BoJ) — for years the only major bank holding rates below zero, which makes the yen the favourite funding currency for the carry trade. How the Bank of Japan's unusual policy shapes the yen I explain separately in a piece on Bank of Japan policy and the yen.
• The Bank of England (BoE) — responsible for the British pound, with decisions that drive GBP/USD and EUR/GBP.
• The Swiss National Bank (SNB) and the Bank of Canada (BoC) — the first stands behind the franc, a safe-haven currency; the second behind the Canadian dollar, closely tied to the price of oil. Both matter for secondary pairs and for reading the mood of the market.

Each of these banks decides on rates according to a calendar published in advance, roughly eight times a year, and every decision comes with a statement and periodic projections. That is a sufficient set to understand where trends on the major pairs come from.

"Investors are perpetually in search of the currency that offers the highest return — capital flows toward the markets with higher interest rates, and it is those flows that drive long-term currency trends." — Kathy Lien, Day Trading and Swing Trading the Currency Market, Wiley, 2016.

How the rate gap turns into a trend

The simplest way to see divergence is to set two banks from one pair side by side and ask which way each of them is heading. It is not the level of rates that counts, but their difference — and whether that difference is widening or shrinking.

Take the dollar and the euro. If the Fed is hiking while the ECB still holds back, the rate differential widens in the dollar's favour and EUR/USD tends to fall. When the roles reverse and it is the ECB chasing while the Fed starts to think about cuts, the gap shrinks and the pair usually rises. The same template works on USD/JPY: as long as the Fed is tightening and the Bank of Japan keeps rates low, the dollar gains against the yen. The strongest and most durable trends are born where two banks move in opposite directions — because then the gap is not only large but still growing.

One caveat is worth keeping in mind. The rate differential is a strong tailwind, but not the only one. In moments of market panic, capital flees into safe-haven currencies — the dollar, the franc and the yen — even against the rate differential. So the picture from central banks is a starting point for a medium-term view, not a guarantee of direction for the next session.

The most common misconceptions

The first and most frequent: the belief that the level of the rate is what matters. In fact the market has priced the current level long ago. The move comes from a change in expectations about the road ahead, and that change is driven by the statement, the projections and the tone of the press conference, not the number itself.

The second misconception is treating each bank in isolation. A currency pair is always the difference between two policies, so a dovish Fed can strengthen the euro even when the ECB changes nothing — because one side of the equation shifted. Looking only at one side of the pair leads to false conclusions.

The third: confusing the minute-by-minute reaction with the trend. Right after a statement the spread widens and the rate can jolt both ways before it settles on a direction. The real effect of policy divergence shows up over weeks and months, not the first seconds after the release.

Three actions to take this week

1. Build a simple central-bank table. Open a spreadsheet and put the Fed, the ECB, the Bank of Japan and the Bank of England in the rows, with three things in the columns: the current rate, the direction (hiking, holding, cutting) and the date of the next meeting. It takes a quarter of an hour and gives you the whole system on a single page.
2. Mark where two banks are diverging. Scan the table and find a pair of banks moving in opposite directions — one tightening, the other easing. The pair made up of their currencies is where the trend usually sits. Watch that one more closely than the rest of the market.
3. Put the meeting dates in your trading calendar. Move the next decisions of the four main banks into your calendar and set a reminder for the day before. That way no meeting catches you off guard, and for the wider backdrop in which trends form, see how fundamental analysis ties central-bank policy to currencies on ForexMechanics.com.