Why rates drive currencies
Money tends to flow toward where it earns the most, adjusted for risk. If UK interest rates are higher than US rates, holding pounds (or pound-denominated bonds) pays more than holding dollars, which tends to support the pound — and vice-versa. This is the core mechanism behind the link between interest rates and exchange rates, and it is why GBP/USD traders watch the Bank of England and the Federal Reserve so closely.
The differential, not the level
What matters for GBP/USD is not the absolute level of UK or US rates but the differential between them — and, crucially, the expected future differential. Markets are forward-looking: by the time a rate decision is announced, the move is usually already priced in. The pound and dollar react to the part that was not expected — a surprise hike, a shift in the projected path, a change of tone. A central bank can move its currency without changing rates at all, simply by changing what investors expect it to do next.
How to read a rate decision for GBP/USD
- Compare to expectations. Check what markets had priced before the meeting; the gap between outcome and expectation is what moves the rate.
- Watch both banks together. A BoE hold is bullish for the pound if the Fed is cutting, and bearish if the Fed is hiking. Always read Cable as a contest.
- Mind the guidance. The statement, the vote split, the projections and the press conference often matter more than the headline number.
- Think in paths, not points. The market trades the whole expected trajectory of rates over the coming year or two, not just the next meeting.
Rates, inflation and the real yield
Interest rates do not move in isolation — they respond to inflation. A currency backed by high nominal rates but even higher inflation may be unattractive in “real” (inflation-adjusted) terms. The most durable currency strength tends to come from positive real yields: rates comfortably above inflation. That is why GBP/USD often reacts as much to CPI surprises as to the rate decisions themselves.