Every graded card price rests on a denominator nobody watches closely: how many slabs exist. PSA publishes a snapshot; we record it every day, which means we hold something the price guides do not, a growth rate. Pair that with our verified PSA 10 sold medians and you can watch scarcity decay in real time. The result over our first measured window is blunt: registry growth is a tax on price, and the market pays it within weeks, not years.
The tape, card by card (registry growth vs verified PSA 10 median change)
| Card | Pop now | Pop growth | PSA 10 median move |
|---|---|---|---|
| Mega Dragonite ex, Ascended Heroes | 7,996 | +12.2% (+358/wk) | $1,595 to $1,523 (-4.5%) |
| Pikachu ex, Ascended Heroes | 10,252 | +10.5% (+399/wk) | $2,485 to $2,400 (-3.4%) |
| Umbreon ex, Prismatic Evolutions | 21,003 | +2.0% (+190/wk) | $6,775 to $6,225 (-8.1%) |
| Rayquaza V, Evolving Skies | 18,910 | +0.8% (+63/wk) | $1,565 to $1,400 (-10.5%) |
| Reshiram ex, White Flare | 10,661 | +2.7% (+117/wk) | $1,264 to $1,350 (+6.8%) |
| Victini, White Flare | 5,347 | +2.3% (+53/wk) | $1,338 to $1,575 (+17.7%) |
| Dark Charizard, Team Rocket | 9,591 | +0.9% (+34/wk) | $1,563 to $3,475 (+122.3%) |
| Lugia V, Silver Tempest | 46,264 | +0.7% (+117/wk) | $1,387 to $1,413 (+1.9%) |
Four hundred new Pikachus a week
The Ascended Heroes chase cards are the cleanest specimens. Pikachu ex added roughly 399 slabs to its PSA registry every week of our window; Mega Dragonite ex added 358. Those are not old cards resurfacing, they are fresh submissions from a set still being ripped by the case. Both cards' verified PSA 10 medians fell during the same seventeen days while the broader index rose. Nothing went wrong with demand. Supply simply showed up faster than buyers did, and each new slab bid against the last one.
Now look at the other end. Dark Charizard from Team Rocket added 34 slabs a week to a registry of 9,591, growth of less than one percent, and its PSA 10 median went from $1,563 to $3,475 in the same window. A 1999 card's registry is nearly closed: the attic copies that could gem have mostly been found. When demand arrives at a closed registry, price is the only thing that can move.
What to do with it
Before paying a scarcity premium on a modern slab, look at the submission rate, not the population. A pop of 10,000 that grows 1% a week is a different asset from a pop of 10,000 that grows 0.1% a week, and six months from now they will have very different denominators. Every graded card page on Moonstone now carries its recorded population series, so the growth rate is one glance away.
Population counts are PSA registry totals recorded daily by Moonstone per card (we record the snapshot on every graded-card page view and via a background job; series here span 15 to 18 days ending August 26, 2026). Price moves compare the earliest and latest verified PSA 10 sold medians recorded in the same window; medians are computed from eBay sold listings individually verified by our pipeline, minimum three sales. Cards shown are all thirteen with a 14-day-plus span on both series and population above 50; the fast/slow split is at 2% window growth. Nothing here is modeled and nothing is financial advice.