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CPI and inflation explained

Headline vs core, why inflation moves bond yields.

Live data

US CPI · Year-over-year inflation

US CPI · Year-over-year inflation
3.78%-55.7%
Latest: 2026-04-01
Data: FRED
47 obs
2.333.995.657.328.982022-05-012024-04-012026-04-01

Source: Federal Reserve Economic Data (FRED). Updated daily.

TL;DR

CPI (Consumer Price Index) measures the average change in prices paid by households for goods and services. It's the most-watched inflation gauge — a single number that can swing every asset class.

Headline vs core

Two flavours. Both are reported.

  • Headline CPI — includes everything (food, energy, housing, services)
  • Core CPI — strips out food and energy, which are volatile
  • Markets typically focus more on core for the trend signal, but headline drives consumer expectations

Why markets care so much

Inflation shapes monetary policy, and monetary policy shapes every asset class.

  • Higher inflation → central banks raise rates → bond yields rise → bond prices fall
  • Higher rates → discount rates rise → growth stock valuations compress
  • Higher rates → currency strengthens vs lower-rate currencies
  • Bitcoin and gold often catch a bid on inflation surprises (or sell off, depending on the cycle)

How to read a print

CPI releases compare against consensus expectations.

  • Hotter than expected — bullish dollar, bearish duration (long bonds)
  • Cooler than expected — bearish dollar, bullish duration
  • In-line — usually a non-event unless components surprise
  • Watch shelter and services components — they drive the core trend
Worked example

A hot CPI surprise

Consensus expects CPI to print 3.2% YoY. Actual prints 3.5%.

  1. 1Expected3.2% YoY
  2. 2Actual3.5% YoY
  3. 3Surprise+0.3pp hotter
  4. 410Y yieldJumps from 4.20% to 4.30%
  5. 5Dollar (DXY)+0.7%
  6. 6Nasdaq−1.5% — duration stocks repriced lower
Takeaway

Even small CPI surprises can move every major asset class within minutes. Pros position before; everyone else reacts after.

Common mistakes

What to avoid

  • !Trading the spike intra-minute — spreads gap, slippage is brutal
  • !Watching only headline CPI and ignoring the core trend
  • !Forgetting that CPI is backward-looking — markets anticipate the next print, not the last one
  • !Treating one print as definitive — single-month noise is large, trend is what matters
Self-check

Test yourself

Q1What's the difference between headline and core CPI?+

Core excludes food and energy; headline includes everything.

Q2Why do growth stocks usually sell off on hot CPI prints?+

Hotter inflation implies higher rates, which raises the discount rate used to value future cash flows.

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