Inflation and Interest Rates: The Core Driver
Inflation expectations drive central bank rate decisions, which in turn move currencies, stocks, and bonds more than any other macro force.
Inflation and Interest Rates: The Core Driver
If you can understand one relationship in macro trading, make it this: inflation drives interest rates, and interest rates drive everything else. Currencies, stocks, bonds, and gold all dance to the tune set by central banks reacting to inflation.
What inflation is
Inflation is the rate at which prices rise and purchasing power falls. A 3% annual inflation rate means a dollar buys about 3% less one year later. Central banks target low, stable inflation — the Federal Reserve's target is 2%.
The two main measures
| Measure | What it tracks | Why it matters |
|---|---|---|
| CPI | Consumer prices for a basket of goods | Most-watched inflation gauge |
| PCE | Personal consumption expenditures | The Fed's preferred measure |
| Core CPI / Core PCE | Excludes food and energy | Less volatile, better trend signal |
How inflation drives rates
When inflation rises above target, central banks raise interest rates to cool demand. Higher rates make borrowing more expensive, slowing spending and investment. When inflation falls, central banks cut rates to stimulate growth. High inflation → central bank hikes → currency strengthens; low inflation → central bank cuts → currency weakens.
Why traders care
Interest rates are the largest single driver of currency values. Capital flows to where it earns the highest yield. A currency with rising rates attracts investment; a currency with falling rates loses it.
| Scenario | Currency impact | Equity impact |
|---|---|---|
| Rising inflation + rate hikes | Bullish | Bearish (higher discount rate) |
| Falling inflation + rate cuts | Bearish | Bullish (cheaper money) |
| Sticky inflation, no action | Mixed | Volatile |
The real interest rate
What matters is the real rate — nominal rate minus inflation:
Real rate = Nominal interest rate − Inflation rate
A 5% nominal rate with 6% inflation is a negative real rate, which is stimulative. A 2% rate with 1% inflation is a positive real rate, which is restrictive. Higher rates raise the discount rate in stock valuations, lowering the present value of future earnings — growth stocks get hit hardest.
What to watch
- CPI and PCE prints — monthly inflation data
- FOMC statements and dot plot — rate path guidance
- Wage growth — input cost pressure
Common mistakes
- Chasing the headline — markets react to the surprise vs. forecast, not the number alone
- Ignoring expectations — an expected 25 bp hike moves nothing; a surprise moves everything
Master inflation and rates, and you have the backbone of macro trading.