What 'Market Cap' Means for a Pokémon Card (and Why We Use Median Sales)

Borrowing “market cap” from the stock market is the fastest way to compare two cards that have nothing else in common. A $40 card with thousands of graded copies can represent more total value than a $400 card with a handful. This page explains exactly how we build the number, the choices behind it, and the cases where it lies.

The definition

For a card at a given grade, market cap is simply price × population: the robust market price multiplied by the number of graded copies known to exist at that grade. Sum across grades (and raw, where we can estimate it) and you get a single figure for “how much value is locked in this card.” It is the same idea as shares outstanding times share price — and it has the same caveat: it is a notional total, not money you could realise by selling everything at once.

Why the median of recent sales — not the last sale

A single “last sold” price is the worst number you can anchor to. One eccentric auction, one lowball private deal, one mis-graded slab, and the mark is wrong. We use the median of recent sales within a grade because the median ignores the extremes: a single outlier high or low barely moves it. That is the same robust mark we use across the screener, the heatmap and portfolio valuations, so every surface agrees with every other.

The last sale tells you what one person paid. The median tells you what the market thinks.

One base currency, always

Pokémon cards trade in yen, dollars and euros at the same time. To compare them we convert every sale into a single base currency (USD) at ingest, store that, and convert to your display currency only for the final number on screen. That keeps a Japanese card and an English card on the same axis instead of drifting with exchange rates inside the data.

Grade is never mixed

A PSA 10 and a raw copy of the same card are different assets with different buyers. We never average across grades to make a mark. Every sale is tagged with its grade on the way in, and a price is always the median within one grade. When you open a card like Charizard from Base Set, the grade ladder shows each grade priced on its own — that separation is what makes the per-grade market cap meaningful.

Where the number can mislead

Thin volume

If only two copies traded last month, the median is honest but fragile — it describes a market that barely exists. We surface volume alongside the mark precisely so you can discount a confident-looking price that rests on almost no trades.

Population is a floor, not a census

Graded population counts slabs that have been submitted and reported. Raw copies in shoeboxes, ungraded collections and un-reported crossovers are invisible. So population understates true supply — treat market cap as a relative ranking signal, not an exact balance sheet.