How to read a population report
Grading. . 1 min read.
Each grading company publishes how many copies of a card it has graded, broken down by grade. That table is the supply half of the price, and it is free to look at.
What it actually counts
It counts cards that company has graded. Not cards that exist. Not cards graded elsewhere. Not raw copies sitting in collections. Understanding that boundary prevents both of the common errors.
Error one: assuming the population is the print run
A population of 40 at the top grade does not mean 40 exist. It means 40 have been graded there so far. If the card is popular and recently released, that number will keep rising, and every new copy dilutes the scarcity you paid for.
Error two: ignoring the shape of the distribution
The interesting figure is not the count at the top grade, it is the ratio. A card with 900 graded and 40 at the top is genuinely hard to find in that condition. A card with 60 graded and 40 at the top is easy to find in that condition and simply has not been submitted much.
The second card looks scarcer by count and is not. That inversion is the single most useful thing a population report tells you.
Using it before you submit
If very few copies reach the top grade, that is evidence about the card manufacture, usually centring or a surface issue common to the print run. It should lower your expected grade in the sum in is grading worth it, and it is part of the price mechanism described in what grading does to the price.
The full guide
What grading does to the price
A graded card and a raw card are different products. Here is what the slab is actually buying.