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Beta Release: JK Index is in active development. Data coverage is expanding and you may see gaps or inconsistencies as we iterate. Feedback is welcome.
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Introduction

JK Index is a collector-driven TCG market intelligence layer for pricing context, historical sales, portfolios, marketplace action, and Before the Slab.

Updated 2026-06-03

JK Index started as a collector-driven pricing and market intelligence platform. The original problem was simple: TCG market data is fragmented, raw and graded prices are often blended together, and collectors are forced to make decisions across eBay, TCGPlayer, PriceCharting, grading reports, Discord, Instagram, and private intuition.

The product has evolved. Pokémon is still the clearest wedge because the market is liquid, emotional, and full of condition-sensitive decisions. But the platform is no longer only a Pokémon price index. JK Index is becoming a market intelligence layer for TCG collectors.

What the platform does today

JK Index gives collectors and sellers a single place to search, compare market context, track portfolios, and act through marketplace surfaces. The data layer separates raw and graded signals where the product has enough structure to do it honestly.

The same foundation now supports broader TCG infrastructure: catalog identity, historical sales, portfolio tracking, Instant Listings, marketplace beta rails, and Before the Slab.

  • Search and pricing context for supported TCG products.
  • Historical sales and market context that avoid treating every comp as equal.
  • Portfolio tracking for collectors who want a clearer view of what they own.
  • Marketplace action through Instant Listings and public listing surfaces.
  • Raw-to-graded prediction markets through Before the Slab practice markets.

Why this exists

Collectors already build mental models from messy inputs. Shops already make buy-list and showcase decisions from incomplete comps. Graders, sellers, and buyers already price uncertainty before a card receives a final grade.

JK Index exists to make those signals more legible. Not by pretending every market is solved, but by building the product surfaces and data rails that make collector behavior easier to read and easier to act on.