CATEGORY MOMENTUM, READ AT A GLANCE.

Heat Index — frequently asked

What is the Heat Index?

The Heat Index scores eight collectible categories 0-100 by blending public ask prices, sold-listing signals, and community interest from live marketplace data. It is an editorial composite, not an appraisal.

How often is it updated?

Category snapshots capture on a scheduled cron. Each tile shows an 'AS OF' date-stamp; if the newest snapshot is older than 36 hours a refresh-overdue banner appears at the top of the board.

What does 'ON FIRE', 'HEATING', or 'COOLING' mean?

Status labels reflect the direction and pace of recent price signals for the category's top movers. ON FIRE marks the fastest 7-day movement; HEATING is meaningful positive drift; COOLING is flat or negative drift. None of these labels forecast future price.

Are the prices appraisals?

No. Every number on Age of Millennials is a marketplace signal derived from live eBay listings and, where matched, PriceCharting reference prices. Always verify condition, authenticity, and recent sold signals before buying.

Where does the data come from?

Live eBay Browse API listings for each tracked signal, filtered through per-query must / negative keyword sets and a 1.5x IQR trim to remove outliers. Reference prices are sourced from PriceCharting where a confident match exists.