---
title: Core CPI
description: Core CPI explained: why inflation ex food and energy moves markets to the second decimal, how desks decompose it, and a worked 0.1pp-miss example.
source: Helious
canonical: https://helious.io/learn/core-cpi
---

# Core CPI

**Core CPI** is the Consumer Price Index excluding food and energy: the inflation measure markets treat as the signal, with headline CPI as the noise. Food and energy prices swing with weather and oil politics; stripping them out reveals the underlying trend the Fed can actually influence.

The release, at 8:30 a.m. ET around mid-month, is routinely the biggest scheduled volatility event on the calendar outside payrolls. Markets trade the **month-over-month core figure to the second decimal**: the gap between 0.2% and 0.3% m/m compounds to nearly 1.2 points of annualized inflation, enough to shift the entire expected Fed path. Desks also decompose instantly: shelter, core goods, and “supercore” (core services ex-housing) each carry separate policy weight.

- Consensus forms tightly, so a 0.1pp miss is a genuine surprise, often a full z-score or more.
- The Fed’s formal target is PCE inflation, but CPI lands first each month, so it moves markets more.

**Worked example:** Consensus expects core CPI at +0.3% m/m; it prints +0.2%, with year-over-year easing from 3.1% to 2.9%. Within a minute the 2-year yield drops 11bp, fed funds futures add 60% odds of an earlier cut, and equity futures pop 0.8%, all from one tenth of a percentage point.

## Questions

### What is core CPI and why does it exclude food and energy?

Core CPI is the consumer price index with food and energy stripped out, because those two are volatile enough to hide the underlying trend. The Fed watches core because it is a better read on where inflation is heading than the headline.

### What did core CPI print at?

Helious captures every CPI release the second it publishes, with the actual against the forecast and the surprise in standard deviations, on [the core CPI series page](https://helious.io/data/core-cpi). The next release date and time are published there too.

### Why does core CPI move the bond market so much?

Because it is the cleanest monthly read on whether inflation is sticky, which is what the Fed's next move depends on. A hot core print is bearish Treasuries and hits the front end hardest. Helious scores the direction and the size of every surprise as it prints, on [the data hub](https://helious.io/data).

## Live data

Helious measures this and publishes the current figures at [https://helious.io/learn/core-cpi](https://helious.io/learn/core-cpi), and through the get_auctions and get_rates_and_curve tools on its MCP server at https://helious.io/mcp.