How to read the US CPI report

What CPI is and how it is released

CPI measures the average change over time in prices paid by urban consumers for a basket of goods and services, such as food, gasoline, rent, medical care, and airfares. It is published monthly by the US Bureau of Labor Statistics (BLS), usually around the middle of the month, covering the previous month.

The report is released at 8:30 AM Eastern Time, before the regular US stock market session opens. Futures markets are trading at that moment, so the first reaction often shows up in index futures, Treasury futures, and the US dollar within seconds. Trading conditions can change quickly around the release, and many traders check the economic calendar so the timing does not catch them off guard.

• Publisher: US Bureau of Labor Statistics (BLS)
• Frequency: monthly, covering the prior month
• Release time: 8:30 AM ET
• The release date for each month is posted in advance on the BLS schedule

Headline vs core CPI

Headline CPI includes everything in the basket. Core CPI excludes food and energy, which tend to swing sharply for reasons such as weather, supply disruptions, or oil market moves that may not reflect broader inflation trends.

Many traders and economists treat core CPI as a better guide to underlying, persistent inflation, while headline CPI reflects what households actually experience. The two can send different messages in the same month. For example, a drop in gasoline prices can pull headline lower while core stays firm. Reading both, and noticing when they diverge, gives a fuller picture than either one alone.

Month-over-month vs year-over-year

The report shows price changes in two main ways. Month-over-month (MoM) compares this month to last month and is usually seasonally adjusted, meaning it is corrected for normal calendar patterns. Year-over-year (YoY) compares this month to the same month a year earlier.

MoM figures show recent momentum and tend to get the most attention on release day, because they show what changed most recently. YoY figures are smoother and are how inflation is usually discussed relative to the Federal Reserve's 2% goal. YoY can also be affected by base effects: an unusually large or small move a year ago can make the yearly rate rise or fall even if this month was ordinary.

• MoM: recent pace, more volatile, often the focus at 8:30 AM
• YoY: broader trend, influenced by what happened a year ago
• Small differences in MoM figures can matter, since they compound over a year
• Ask whether a YoY change is driven by this month or by the month dropping out from a year ago

Shelter, services, and the details beneath the headline

Shelter is the largest single component of CPI. It includes rent and owners' equivalent rent, an estimate of what homeowners would pay to rent their own home. Because these measures are built from leases that reset slowly, shelter tends to lag changes in market rents, sometimes by many months.

Traders also watch services prices, since services are tied closely to wages and have historically been slower to cool than goods prices. Some analysts look at core services excluding shelter to judge labor-driven inflation. Breaking the report into goods, shelter, and other services can show whether inflation pressure is broad or concentrated in a few categories.

• Shelter: rent and owners' equivalent rent, slow to adjust
• Core goods: items like cars, apparel, and household goods
• Core services: medical care, insurance, transportation services, and more
• Look for whether one category explains most of a surprise

Why CPI matters for the Fed and yields

The Federal Reserve targets 2% inflation over time. Its preferred gauge is the PCE price index, not CPI, but CPI comes out earlier and strongly shapes expectations about future interest rate decisions. The Fed's rate-setting committee, the FOMC, meets eight times a year.

When CPI runs hotter than expected, markets have tended to price in tighter policy, meaning higher rates or fewer cuts. This can push Treasury yields up, especially shorter-term yields that are most sensitive to Fed expectations. Cooler readings have tended to work the other way. Changes in yields can then feed into stock valuations and the dollar, though the links are not mechanical and exceptions are common.

Surprises vs expectations, and a note on Canada

Before each release, economists publish forecasts, often summarized as a consensus estimate. Markets usually price in much of that expectation ahead of time, so the reaction tends to depend on the surprise: how far the actual figure lands from consensus, and in which components. A reading in line with expectations may produce little lasting reaction, while a surprise in core MoM can move markets more. First moves sometimes reverse as traders digest the details, revisions, and broader context such as positioning and other recent data.

Canada publishes its own CPI through Statistics Canada, also at 8:30 AM ET. The Bank of Canada targets 2% inflation, the midpoint of a 1% to 3% range, and watches core measures such as CPI-trim and CPI-median. Canadian CPI can influence the Canadian dollar and Canadian bond yields in a similar expectations-driven way.

• Compare actual figures to consensus for headline and core, MoM and YoY
• Note which components drove any surprise
• Watch whether the initial reaction holds or fades
• Consider how the result fits with recent jobs data and Fed communication

Key terms

CPI (Consumer Price Index)

A monthly measure of the average change in prices paid by urban consumers for a basket of goods and services.

Core CPI

CPI excluding food and energy, used to gauge underlying inflation trends.

Month-over-month (MoM)

The percentage change from the previous month, usually seasonally adjusted.

Year-over-year (YoY)

The percentage change from the same month one year earlier.

Owners' equivalent rent

An estimate of what homeowners would pay to rent their own home, a major part of the shelter category.

Base effect

A change in a yearly rate caused by an unusual reading a year earlier rather than by the latest month.

Consensus estimate

The typical forecast from economists for a data release, used as the benchmark for judging a surprise.

PCE price index

The Federal Reserve's preferred inflation measure, published by the Bureau of Economic Analysis after CPI.