What is the CPI inflation report, and why will traders be watching it on Tuesday?

The consumer price index, or CPI, is a monthly report from the US Bureau of Labor Statistics that tracks how prices changed for a basket of everyday goods and services, like food, gas, rent and cars. You'll usually see two numbers: the change from the month before and the change from 12 months earlier. In the last report, for September, prices rose 0.6% in one month and 3.7% over the year, with gasoline a big driver. The October report comes out Tuesday, Nov. 10, at 8:30 a.m. Eastern (10:30 p.m. Korea time).

You'll also hear about "core" CPI, which strips out food and energy because those prices swing a lot, so it can give a steadier read on the underlying trend. In September, core CPI rose 0.3% for the month and 2.6% over the year, well below the 3.7% headline, which shows how much energy was pushing the main number up. For October, FactSet's consensus expects about 0.24% for headline CPI on the month and about 0.2% for core, according to Morningstar.

Why do markets care? Inflation shapes what the Federal Reserve does with interest rates, and rates affect borrowing costs, bond yields and stock prices. As of Sunday, CME FedWatch showed traders pricing about 78% odds of a quarter-point Fed hike in December, per CNBC, so a number far from expectations can move markets fast. A good habit is to compare the actual number with the estimate and check both headline and core instead of reacting to one figure. Got questions about CPI or inflation? Ask below, there are no silly questions here.

Sources: CNBC (Oct 14 and Nov 8, 2026), Reuters via Investing.com (Oct 14, 2026), Morningstar October CPI preview (Nov 2026), Nowflation CPI release calendar.