How Our Market Data Works

Each sale record keeps the marketplace it came from. Sources fall into two groups: places where a card changed hands, and places that merely list one for sale. Only the first group is ever counted as a sale.

Collectible sources are added as they are connected. A marketplace appearing on this list means its records exist in our sales table, not that every sale on that marketplace is captured.

A record is treated as a completed transaction only when all of the following are true:

• The marketplace is a sold-sale source, not a live-listing source.
• A positive final sale price is recorded — not a bid, a reserve or an asking price.
• A sale date is recorded.
• The listing describes a trading card rather than apparel, footwear or another collectible.
• The record does not link to a social media post. Promotional posts advertise an auction that is still running and are never counted as sales.

Transaction types. Auction results are recorded at the final price. Fixed-price purchases are recorded at the price the item sold for. A best offer is recorded once the accepted amount is known; until then the visible asking price stays a listing price and is not counted. Records that are withdrawn or cancelled are not presented as sales, and a record without a final price is never shown as one.

Asking prices. Current listings are shown alongside confirmed sales but in their own section, always labelled as asking prices. They are never mixed into medians, averages or charts.

We do not publish a formal verification badge we cannot support. Where a listing's card details are incomplete, the sale is labelled as a partial match rather than presented as an exact card.

Sales are collected by scheduled jobs that run daily, and the newest records appear as each job completes. Every sale keeps its own sale date, so a sale that happened three weeks ago is still dated three weeks ago no matter when it was collected.

Different sources finish at different times: eBay comps and marketplace listings usually refresh overnight, while auction results appear after the house publishes them. That means a period's totals can still grow for a day or two after the period ends.

The same sale can arrive from more than one pipeline. Records are de-duplicated before they are counted or compared, using the source's own identifier first, then a stored de-duplication key, then a combination of listing title, price, sale date and marketplace.

Two genuine sales of the same card on the same day at the same price are still two sales — a card resold quickly is real market activity, so de-duplication only removes records that describe the same transaction.

Each sale is attached to a card identity made of:

• Athlete
• Sport and league
• Card year
• Manufacturer and set
• Card number
• Parallel or variation
• Grading company
• Grade

Where the marketplace supplies these as structured fields, those values are used. Where it does not, the year, set, parallel and grade are read from the listing title — the product name is usually there even when the field is empty. A sale is marked as an exact match only when the year, set and card number are all known; otherwise it is marked as a partial match, and it is compared only against other partial matches of the same card.

Grades are never combined. A PSA 9 copy of a card is compared with PSA 9 copies. PSA 8, PSA 10, BGS and raw copies each have their own history, and a card with no numeric grade is labelled separately from a graded one.

We do not use fuzzy card matching to fill in a thin market. If a card cannot be identified with confidence, its sales are not pooled with a different card, even when the two look similar.

Where the price guide shows an estimated value, it is calculated from recorded sales of that card and grade — never from a listing price. The estimate prefers the most recent evidence:

1. 1Three or more sales in the last 30 days, weighted toward the most recent sales.
2. 2Three or more sales in the last 90 days, weighted the same way.
3. 3The median of three or more older sales.
4. 4A single recorded sale, shown as very limited evidence rather than a confident value.

Grade, recency and the number of recorded sales all affect the figure, and the explanation shown with a value states which of these rules produced it. An estimate is a reading of past transactions, not a guaranteed selling price and not a formal appraisal.

• Coverage varies by card, grade, marketplace and time period. A scarce card may have one recorded sale, and a common card may have hundreds.
• Not every sale on a connected marketplace is captured, and private sales are never captured.
• Some sources do not report the card number, parallel or grade. Those sales still count as transactions, but they are matched more cautiously.
• Asking prices, reserves and estimates are not sales and are never treated as sales on this platform.
• An estimated value is not an offer, a guarantee, or a formal appraisal. Independent verification is always recommended before buying or selling.