Methodology: every number, explained

Prices

Market price is TCGplayer's own estimate of a fair near-mint sale price for a product, published once a day. We also store low, mid and high listing prices for every printing (Normal, Foil, Holofoil, Reverse Holofoil, 1st Edition and so on). When a page shows one price for a card, it is the market price of the highest-priced printing; all printings are listed on the card page.

Daily snapshots begin on February 8, 2024. Sealed products (boxes, packs, decks) are tracked with the same fields and shown separately.

Change over a period

A card's 7-day change is today's market price against the market price exactly seven days earlier, for the same printing. If either day has no price, the change is shown as a dash rather than estimated.

Indices

The market, each game and each set have a chain-linked, price-weighted index. For each day, the sample is every single-card printing that has a market price both today and yesterday and was worth at least $1 yesterday. Sealed products are not part of any index; set and game values count single cards only. The index moves by the ratio of the two sums and chains from the previous day. Base is 100 on the first day of data for that scope. See the index page for why chaining matters.

Market value

The sum of current market prices across all priced printings in a scope. It is a size measure, not a valuation of any collection — a card counts once per printing, regardless of how many copies exist.

Movers

Top 50 gainers and losers by percentage change for a period, among single cards worth at least $1 both before and after the move. Ties are broken by current price. Sealed products are excluded from movers and shown on their own pages.

Against the tide (anomalies)

For cards worth at least $5 a week ago, we compute the 7-day change and the median 7-day change of all such cards in the same game. To keep single-sale repricings out, both ends of the comparison are medians of three days, not single days. A card is listed when its change differs from the game’s median by more than 15 percentage points. The feed is sorted by the size of that gap.

Heatmap

Tile area is proportional to market value; color is the index change over the chosen period. Intensity scales linearly up to ±3% and is capped there so that one outlier does not wash out the rest.

Where it's cheaper

Cardmarket prices come from open per-game APIs and are stored in euros. For comparison they are converted at the European Central Bank reference rate, refreshed every night; the euro figure is always shown alongside. The gap is TCGplayer price against converted Cardmarket price. Shipping, taxes and condition are not included — this is a price comparison, not a landed-cost calculator.

Tiers

Games are grouped by market value: tier A above $100K, tier B $10K–$100K, tier C below. Tiers change the ticker and the default heatmap only; every game gets the same pages.

What we don't do

• No graded (PSA/BGS/CGC) prices, no condition tiers.
• No sold-listing data from eBay; it is not available to third parties.
• No estimated history before February 8, 2024.
• No manual adjustments to individual prices. We never type a number in by hand.

When the market price lags the listings

A market price is a record of what copies sold for, not an offer. When a card goes months without a sale, that record stays where the last sale left it while sellers move on — and the site ends up showing $18 for a card whose cheapest copy asks $208.

We don't touch the number: it is what the source published, and we never type prices in by hand. Instead the printing is flagged when its market price is below 65% of the cheapest current listing, and the card page says so in plain words next to the price. Flagged printings are kept out of movers and out of the anomaly feed, because the jump you see when such a price is finally refreshed is a bookkeeping update, not a market move. On Oct 17, 2026 this covered 8,998 of 435,063 priced printings — 2.1%.

One-day outliers

A source occasionally publishes a single day that contradicts the days around it — a card priced at $166 sitting between two days at $1,100, for instance. That is a glitch in the feed, not a market move: a real move pulls the neighbouring days with it.

Such days are excluded from charts and from the moves we publish. The rule is mechanical and has no discretion in it: a day is dropped only if its price is less than half of both the day before and the day after, or more than double both. Nothing else is filtered, and the underlying record keeps every value the source sent. In practice this removes about one point in a thousand.