Core CPI
CPI excluding food and energy prices, which are more volatile and less tied to underlying inflation.
Core CPI is the consumer price index excluding food and energy. Those two components swing with weather, harvests, oil and gas prices, so removing them gives a steadier read on underlying inflation. It is calculated by the same agency and released with the headline CPI.
On our site, core CPI is shown beside headline CPI. A large gap between them usually means food or energy is driving the headline, which policymakers tend to see as less persistent.
Traders care because core CPI is the figure most closely tied to policy expectations, so a core surprise often moves rates more than the headline does.
Worked example (illustrative numbers, not real data): headline CPI rises 0.5 percent in a month, but food and energy account for most of the gap. Core CPI rises 0.2 percent. The headline looks hot, but the core print suggests less persistent pressure, so the market may react less.