ForecastingStocks

Two more central banks complete the picture for the world's major currencies: the European Central Bank (ECB) and the Bank of Japan (BoJ).

The ECB — one bank for many nations

The ECB sets policy for the entire Eurozone, with a primary mandate of price stability (inflation near 2%). Its key lever is the deposit rate. The difficulty is uniformity: one rate must fit Germany and Italy at once, so the ECB often moves more cautiously than the Fed and watches the gap between member states' borrowing costs (the "spread"). For traders, the Fed-versus-ECB balance is the main driver of EUR/USD: when the ECB is relatively hawkish, the euro rises; when it lags, the euro falls.

The Bank of Japan — the great exception

For decades the BoJ ran the world's most extreme easy policy: rates near or below zero, massive QE, and yield curve control (capping long-term bond yields). Its goal was to escape years of deflation. This made the yen the world's premier funding currency — investors borrowed cheap yen to buy higher-yielding assets elsewhere, the classic yen carry trade.

Why the BoJ is worth watching closely

When a central bank that has been ultra-easy for years starts to tighten, the effect is outsized. A BoJ shift can trigger a sudden unwind of the yen carry trade: investors buy back yen to close positions, the yen surges, and the assets bought with borrowed yen get sold — a shock that can ripple across global markets. USD/JPY is the pair to watch.

The takeaway

Currencies are a relative game. EUR/USD is the Fed against the ECB; USD/JPY is the Fed against the BoJ. You are always comparing two central banks, not judging one in isolation. The interest-rate differential between them is the gravity that pulls a pair.