Methodology · Read This Once
The worked example · Ethan Holliday 1st Bowman Chrome Auto · live eBay listing

How Our Prices Work
Five Numbers, One Rule

This site shows five different kinds of numbers, and they are not interchangeable. Here's what each one is, where it comes from, and which to trust when they disagree. The one rule behind all of them: we never invent a number, and every number carries its date and its source.

📊 Solds > asks, always 🕑 Every number dated ⚖️ Misses graded in public
1 · The Truth

Sold Comps

What a card actually traded for — completed sales from PriceCharting (Pokémon) and SportsCardsPro (sports). This is the ranking basis for the Bangers board, the marking basis for every set index, and the only basis we ever grade a call against. When a sold comp and anything else on this page disagree, the sold comp wins. If the candle is green, more people bought than sold that day — that's the only absolute truth in this market.

2 · The Optimistic Side

Live Asks

What sellers are asking on eBay right now, pulled live through our own API. Asks are wishes, not trades — so every ask on this site is labeled "asks" and never dressed up as a sold price. When we publish an ask mark it goes through the house trim: drop the two cheapest listings (bait and "read description" traps live there), take the median of the next ten, shipping included. No number publishes unless at least six clean listings survive with a spread under 4x — when a market fails that gate, the page says so instead of carrying a fake number.

3 · The Nightly Tape

Engine Marks

Every night an automated engine re-marks a fixed list of tracked cards — the Signal Board names and a few more — using a trimmed median of the cheapest verified asks. Engine marks power the Signal Board and flow into the Vault as daily chart points. They are ask-side and labeled that way; they can and do diverge from sold comps, and we show both rather than blending them.

4 · The Big Picture

Index Levels

Each set index is a basket of sold marks divided by a divisor, launched at 100.00 — so the level IS the cumulative return since inception. When cards enter the basket the divisor adjusts (and the adjustment is logged) so composition changes never move the level; only prices do. Re-marked every Monday from sold comps. An index is a measurement, not a recommendation.

5 · The Honest Stand-In

Proxy Feeds

The engine tracks a specific list of cards — not every card exists in it. If you Vault a card without its own feed (say, a Sapphire when the engine tracks the Chrome auto), the Vault can follow a related card's feed instead, marked with an orange PROXY badge naming exactly what differs. A proxy shows you a related market's direction; it is never presented as your card's own price. Your own logged prices always take precedence on your charts.

When They Disagree

Which Number Do I Trust?

Solds beat asks. Dated beats undated. Your own logged purchase beats everything, because you know what you actually paid. And when one of OUR published numbers turns out wrong, it doesn't quietly disappear — it gets graded on the track record, misses included. That page is the reason you can trust this one.