What it is

A grading company’s population ("pop") report counts how many copies it has graded of a specific card at each grade. A card with only a handful of 10s is far scarcer — and usually far pricier — than one with thousands.

How to use it

Compare the pop at your grade to the grades just below it. A steep drop (many 9s, few 10s) signals a large gem-mint premium; a flat curve signals less scarcity value. Pair the pop with realized sales to judge whether a price is justified.

Scarcity meets real comps

Population explains the why; comparable sales tell you the how-much. Slabline prices each card from real sales at its exact grade, so the value you see already reflects how scarce — and how sought-after — that slab is.