Consumer Price Inflation: Definition & Meaning | Bondfish
Consumer price inflation is the year-over-year percentage change in the Consumer Price Index (CPI), a fixed basket of goods and services — food, housing, energy, transportation, medical care — that measures how much prices paid by typical households have risen.
What it means
Statistical agencies (the U.S. Bureau of Labor Statistics, Italy's ISTAT, Eurostat for the euro area) price the same representative basket every month and compare it with a year earlier to produce the headline CPI figure. Core CPI strips out volatile food and energy prices to show the underlying trend. In the U.S., headline CPI inflation was 3.4% year-over-year in August 2026, while core CPI ran at 2.4%, the lowest core reading since March 2021, according to Trading Economics.
CPI is the most widely quoted inflation figure because it maps directly to household cost of living, but it is one of several measures — alongside the PCE price index the Fed targets and the Producer Price Index, which tracks costs earlier in the supply chain.
Why it matters for bond investors
CPI releases are among the most market-moving data points for bonds because central banks set policy rates partly in response to them. A hotter-than-expected CPI print typically pushes bond yields higher (and prices lower) as markets price in a more hawkish central bank path; a cooler print tends to do the opposite. Investors holding inflation-linked bonds (U.S. TIPS, euro-area inflation-linked government bonds) have their principal or coupon adjusted directly by CPI, making the index a direct input into those securities' returns.
Related terms
This definition is for general information only and is not investment advice. Bond investing involves risk, including possible loss of principal.