How HobbyCardIndex Calculates Card Prices
HobbyCardIndex publishes real-time price data for over 16 million sports and trading cards, calculated by the HCI pricing model from completed sales across the hobby, with grading-service population reports alongside. Prices are recalculated every night.
Our Data Sources
Every price on HobbyCardIndex comes from real completed sales. We never publish a “predicted” value when there are no sales behind it. Below is how the pricing model works and what goes into it.
The HCI Pricing Model
Every card’s price is calculated by our own pricing model. It gathers completed sales from across the hobby, including eBay, Fanatics Collect, Goldin, Heritage and other marketplaces and auction houses, and works them into one current price for each card at each grade. Coverage spans more than 16 million cards across sports (baseball, basketball, football, soccer, MMA), Pokémon, Magic: The Gathering, and other trading card games.
Every price on the platform comes from this model: market movers, the category heatmap, the grade grid, portfolio values and grading-ROI estimates. Because one model produces every number, when a price looks wrong we know exactly where to look.
eBay Browse & Find APIs, Sold-Listing Verification
For historical sales context and recent-comp tracking, HobbyCardIndex pulls sold-listing data via the eBay Browse and Find APIs. We consume completed transactions only-both auction-format and “Buy It Now” sales that have closed-filtered by listing condition where available.
eBay sold listings are also shown on their own, so you can see the actual sales behind a card next to its HCI price.
Grading Service Population Data, PSA, BGS/Beckett, CGC, SGC
Population reports from PSA, BGS/Beckett, CGC, and SGC feed population-weighted price modeling and grading-ROI estimates. A PSA 10 on a card with 12 known examples is worth more than a PSA 10 on a card with 4,200 known examples; pop data is what makes that distinction visible. We pull public pop-report data on a regular refresh cycle and surface it alongside grade-ladder pricing on card-detail pages.
Update Cadence
The pricing model runs on a nightly refresh cycle, typically completing around 2 AM UTC. Card-level prices are updated within 24 hours of new sales. eBay sold-listing data refreshes continuously during market hours and is aggregated on the same nightly cycle. Historical price snapshots are stored as a time-series dataset (TimescaleDB hypertable), which means every prior nightly value is retained indefinitely-the history behind a price chart is real daily data, not an interpolation.
If a card’s price moves significantly intraday on eBay, the sold-listing surface reflects that immediately; the valuation number updates on the next nightly run.
How to Read Our Price Data
Each card-detail page shows up to seven price columns. Here is what each one means:
| Column | What it represents |
|---|---|
| Loose / Raw / Ungraded | Current market value for the card outside a graded slab. This is the baseline price and the most liquid market for most cards. |
| PSA 10 | Gem Mint grade from PSA (Professional Sports Authenticator). PSA 10 is the highest standard grade and typically commands the largest premium over raw. |
| PSA 9 | Mint grade from PSA. For high-volume modern cards, PSA 9 often represents the most realistic outcome from a typical submission. |
| PSA 8 | Near Mint to Mint from PSA. Useful for vintage cards where PSA 8 is a strong result and commands meaningful value over raw. |
| BGS 9.5 | Pristine grade from Beckett Grading Services. Note: this column is internally labeled BGS 10 for historical reasons, but it stores BGS 9.5 data-Beckett’s BGS 9.5 is the equivalent premium-grade benchmark in most market comparisons. True BGS 10 Pristine is extremely rare and falls back into this column only when BGS 9.5 data is unavailable. |
| CGC 10 | Pristine 10 from CGC (Certified Guaranty Company). CGC is the dominant grading service for Pokémon and MTG, and competitive with PSA/BGS on modern sports. |
| SGC 10 | Pristine 10 from SGC (Sportscard Guaranty). SGC is particularly strong for vintage baseball and commands premium premiums on high-grade pre-war cards. |
| Day-over-Day Change | Difference between today’s price and yesterday’s stored snapshot, expressed in dollars and as a percentage. Positive values are shown in green; negative in red. Powered by the TimescaleDB hypertable described in the Update Cadence section above. |
Not every card has data in every column. If a grade has no data, the cell is left blank rather than filled with a placeholder or estimate. Blank means unknown, not zero.
Our Editorial Standards
HobbyCardIndex maintains a clear line between data (objective: what do completed sales say this card is worth today) and analysis (interpretive: what does the trend suggest about the market for this player). Data is published without editorializing. Analysis, where it appears-in market reports, trend pages, and long-form research pieces-is labeled as analysis and attributes the specific data behind each claim.
If a price looks wrong, the right move is to tell us. Email support@hobbycardindex.com with the card, the price you saw, and what you believe is correct. We log corrections by date and card, and corrections are applied on the next nightly run once verified. We do not pull corrections quietly-if a price was materially wrong on a card for more than 24 hours, we note the correction date in the price history.
No partner, advertiser, or grading service has any input into how individual cards are priced or ranked on HobbyCardIndex. The full structural independence commitments are on the independence page.
About the Team
HobbyCardIndex is built and maintained by the HobbyCardIndex Editorial Team-a collective of collectors, data engineers, and market researchers who work across the platform. The team is responsible for catalog accuracy, data-source vetting, methodology documentation, and publishing the long-form market research and guides on the site. Bylines on specific pieces appear where relevant; this page is the collective voice.
The platform is independently owned. Not a grading service, not a breaker. We do run a marketplace, but sales on it don't feed our prices, which are built from real sold prices across the hobby. The About page and the Independence page have more on the ownership structure and what that means in practice.
Contact
Questions about methodology, data corrections, press inquiries, and partnership questions all go to support@hobbycardindex.com. The contact page has the full breakdown by inquiry type. We aim to respond within one business day.
If you’re a journalist verifying a number or a researcher who wants the underlying data behind a chart, ask-we send source data on request, free of charge.
Try the platform
Free tier, no credit card. Search any of the 16 million+ cards in the catalog, build a watchlist, and see the market-intel dashboard. The basic price tools are not gated.
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