Currencies move on interest rate differentials, trade balances, and where global capital is chasing the best risk-adjusted returns. A strengthening or weakening currency quietly reshapes the earnings of every multinational company you might own.
A currency's exchange rate is, at its core, a relative price — how much of one currency it takes to buy another. That relative price moves as global capital flows toward whichever country offers the best risk-adjusted return at the time. The single biggest driver, tying directly back to the previous two lessons in this track, is the interest rate differential: when one country's central bank offers meaningfully higher rates than another's, capital tends to flow toward the higher-yielding currency to capture that difference, pushing its value up (all else equal).
A country's trade balance — exports minus imports — also matters. A country running a large trade surplus (exporting more than it imports) generates steady foreign demand for its currency, as foreign buyers need it to pay for those exports. A persistent trade deficit works in the opposite direction, creating a steady source of selling pressure on the currency over time.
Currency moves aren't just a forex-trading concern — they quietly reshape corporate earnings. A company that sells heavily overseas but reports in its home currency sees its foreign revenue translate into fewer home-currency dollars when its home currency strengthens (a stronger currency makes exports more expensive for foreign buyers, and shrinks reported overseas earnings on translation) — and the reverse when it weakens. This is why large multinational companies routinely flag currency effects explicitly in their earnings reports.
Three hypothetical scenarios showing how a widening or narrowing interest rate gap between two countries has historically tended to relate to currency direction, all else equal.
| Scenario | Country A Rate | Country B Rate | Rate Differential | Typical Currency A Direction |
|---|---|---|---|---|
| Wide Gap Favoring A | 5.5% | 1.0% | +4.5 pts | Tends to Strengthen |
| Narrow Gap | 3.0% | 2.5% | +0.5 pts | Modest or Mixed |
| Gap Reverses | 2.0% | 4.5% | -2.5 pts | Tends to Weaken |
All else equal, a widening rate advantage for Country A has historically tended to attract capital toward Country A's currency; a reversal tends to reverse the flow — though real currency moves reflect many factors simultaneously, not interest rates in isolation.
Enter a company's overseas revenue share and a hypothetical currency move — see the estimated effect on total reported revenue from translation alone.
Model: overseas revenue = total × overseas share. Translation impact ≈ overseas revenue × (−currency move %), since a stronger home currency reduces the home-currency value of foreign revenue when translated back. Illustrative only — ignores hedging, pricing power, and other offsetting effects.
Answer all five, then hit "Check My Answers" to see how you did. Get one wrong? No problem — the explanation will show you exactly why.
Print-friendly resources to revisit, practice, and dig deeper — no login required.
You've now seen how rates, the yield curve, and currencies move on related forces. The next lesson zooms out further, to how stocks, bonds, currencies, and commodities move together or apart across market regimes.