Notes

Data

Shelf prices for every item listed on traderjoes.com at five stores — Los Angeles (31), Austin (452), New York East Village (546), Chicago South Loop (701), and Chicago Hyde Park (706) — collected monthly. 3,475 items and 340,753 store-month prices from Jan 2024 to Oct 2026. January 2024 – June 2025 comes from the daily scrapes of cmoog/traderjoes (MIT), reduced to the most common price each month. No data exists for July–September 2025.

Trader Joe’s Price Index

A chained, equal-weighted Jevons index, the same construction the BLS uses inside each CPI item category. For each pair of consecutive months, every item priced at the same store in both months contributes its price ratio; the index moves by the geometric mean of those ratios. Items entering or leaving the catalog never move the index. Ratios above 3× or below ⅓ are treated as data errors, and a few items with clearly wrong source prices are left out entirely. Months without a scrape are bridged log-linearly and shown dashed.

The “same items” variant restricts the calculation to items sold in both the first and latest month. It runs higher than the main index: long-running staples have risen faster than the rotating seasonal catalog.

Category and store indexes use the same method on their subsets. Categories are Trader Joe’s own.

Official data

CPI components and BLS average prices are U.S. city averages, not seasonally adjusted, from FRED. The BLS published no CPI for October 2025 due to the federal government shutdown; that month is interpolated and shown dashed.

Download

• All index and FRED series (JSON)
• Item list with current prices (JSON)
• Monthly price history for every item (JSON)
• Any graph can be downloaded as CSV from its toolbar.

Source

github.com/jkane-29/tradercpi. Not affiliated with Trader Joe’s.