FX2026-06-21

What Moves Exchange Rates: Rates, Trade and Sentiment

How exchange rates are set and the key forces that move them — rate differentials, inflation, the trade balance, safe-haven demand, central banks — and how FX feeds into equities and inflation.

An exchange rate is the relative price of one currency against another. A rising USD/KRW means the dollar is getting more expensive and the won weaker. FX moves on many tangled factors, but knowing a few big drivers lets you see the flow.

What an exchange rate is

An exchange rate is the ratio at which two currencies trade. "USD/KRW 1,300" means it costs 1,300 won to buy one dollar. When that number rises, the won is weaker (dollar stronger); when it falls, the won is stronger.

The key forces that move FX

  • Rate differentials. Money chases higher yields. When a country raises rates, demand for its currency rises (a strengthening pull). When the US hikes, the dollar tends to strengthen (the carry).
  • Inflation and purchasing power. A currency with higher inflation tends to weaken over the long run (purchasing-power parity).
  • Trade / current account. Strong exports bring in foreign currency and raise demand for the home currency (a strengthening factor); deficits do the opposite.
  • Safe-haven demand. In a crisis, money piles into havens like the dollar, yen and Swiss franc, strengthening them.
  • Central banks and policy. FX intervention, the direction of monetary policy, and political/geopolitical risk all matter a great deal.

How FX feeds into markets

  • Exporters vs. importers. A weaker home currency helps exporters (price competitiveness) but burdens import-heavy firms.
  • Import prices and inflation. A weaker currency raises the price of imports, stoking inflation.
  • Foreign capital. If a currency is expected to weaken, foreign investors may pull money out to avoid FX losses (a source of equity volatility).

How to read it

  1. Watch it with rate differentials. A currency's broad direction is largely explained by the gap between the two countries' rates.
  2. Compare with the dollar index. The overall strength of the dollar (DXY) tells you whether a move is "about the dollar" or "about the other currency."
  3. Short, sharp moves are sentiment. Crisis-driven flows often reverse quickly.

Indicators worth watching alongside

The Global Market Dashboard shows the dollar index (DXY), USD/KRW, and Treasury yields together. See for yourself how FX interlocks with rates and the dollar.

This article is for informational purposes only and is not investment advice.