How it works

The indices

Each index follows one market and grade — Japanese, English or Chinese Pokémon, or One Piece; raw or PSA 10. Every index works like holding one copy of every card: every card that has been out for six months or more and is worth at least a floor price, weighted by its price, so the line follows where the money is — the way wine and stock indices weight by value. No card counts for more than 2% (or five times an equal share while a market is still small), so one grail cannot carry the line. A new card waits six months because a set's cards fall for their first months while it is still being opened; wine indices wait for the same reason.

We tested this against the plain truth — buying every card on a past date and holding it to today. The old top-100 baskets, picked by price and trimmed of the biggest moves, ran far behind it (Japanese raw since June 2024: +31% against +150% for the cards held); the every-card index lands within a few points in Japanese, English and Chinese. The basket is reviewed on the 1st of every month and the months are chain-linked, so cards joining never make the line jump. Every index starts at 1,000.

The Chinese indices also have a line per era — Sun & Moon, Sword & Shield, Scarlet & Violet — and every market page shows the share of cards rising each week beside the index, for the typical card.

A card that goes quiet keeps its place for up to six months and moves with the rest of the basket meanwhile — the way statistics offices fill in a missing price. When it sells again, its real price counts. This matters because cards often stop selling while their prices fall: an index that simply dropped them would count the rises and miss the falls.

A one-day jump of 3× or more only counts once the next price confirms it, and a card that moves that much in a day moves with the basket until the next review.

Where the prices come from

Japanese Pokémon and One Piece: sold prices from Japan's card market. The daily price is the median of the 3 newest sales in the last 14 days, or the last sale when fewer — a sale older than 14 days is not a price. Before our nightly archive began, each day was rebuilt from the public sales history with exactly this rule, which is why these indices reach back to 2023–24.

Chinese Pokémon: market prices from China's card market, archived every night since August 2026; earlier days come from each card's own price chart on that market, which runs from the card's release, so the Chinese indices reach back to 2023–24. English Pokémon: US price-guide data, archived every night since August 2026; before that, each card's own monthly price history, read for every English set's top cards — picked set by set rather than by today's price, so sets that crashed count as much as sets that soared. The English indices reach back to 2022. The headline English index is Modern (Sword & Shield onwards); Vintage (1999–2007) has its own lines on the English page. Rare cards' guide prices can jump on one odd sale, so the English indices count each card the same, leave out the most extreme 5% of moves at each end, and ignore a price more than 3× away from the card's own recent level unless it holds.

The indices cover the cards Cardian tracks (thousands per market), not every card ever printed.

Pokémon baskets

Every card is tagged with the Pokémon on it, from its English, Japanese or Chinese name (a TAG TEAM card counts for each Pokémon). A Pokémon's basket is its cards priced on both days of the window, each counting the same, at least 5 cards (3 in Japanese and One Piece sold prices).

How sets age

Each set's priciest singles a week after release — up to 15, none over 20% — form a basket set to 100 on that day, then followed weekly for two years. The typical set follows the median week-to-week move of all the sets old enough, so a set dropping out of the sample never makes it jump. Release dates come from our catalogue, or a set's first sales when we have no date.

The PSA 10 premium

For every card with both prices, its PSA 10 price over its raw price; the median across the market. Cards under ¥1,500 / US$10 / CN¥80 raw are left out, because there the grading fee is most of a slab's price. The Japan vs US figure compares the same Japanese card's US price and Japan price in Singapore dollars at the day's rate; pairs more than 4× apart are left out as two different printings matched to one card.

The bottom checklist

Five signals a falling market often shows before it turns: down 10% or more from its 12-month high; the fall slowing (the last week lost less than the 30-day pace); more cards rising than falling this week; cold (fewer cards above their 30-day average than usual over the past year); back above its 4-week average. More ticks = more signals showing. It is a reading, not a forecast.

What we publish

Our own indices, baskets and medians, and the card lists behind our analytics (the cards that moved most, top cards by era, pop vs price, grading gains) — rankings and changes, not another site's price list. Card pages show Cardian's own price and stock.

Updates

Everything is recomputed every night (Singapore time). Prices on card pages are the shop's listed prices at that time; the shop has the live price.