What's More Valuable: Liquidity or Scarcity?

A card's population tells you how many copies exist, but it won't tell you how many buyers show up on the day you want to sell. Patrick Mahomes's 2017 Panini Select rookies show the difference, because two of them have almost the same number of PSA 10 copies and sold at different speeds this summer.

Financial markets have priced that difference for decades. An asset that sells quickly, near its prevailing price and at low cost is worth more than one that takes weeks to move or a discount to clear. Yacov Amihud's 2002 paper built an illiquidity measure out of how much a stock's price moves per dollar traded, and found that investors demand a higher return for owning what is hard to sell.¹

Cards have it worse. There's no central exchange or running bid and ask. Nobody promises to buy on the day you want to sell.

Two Mahomes rookies with almost the same supply

Here is how they sold in the 90 days to Aug. 25, by Card Ladder's count, beside three cards I'll come back to.²³

Let's take the top 2 Mahomes in the table. Nine buyers snagged Silvers over those three months. Only three took a Premier.⁴⁵

The Field Level last sold for $4,506 on Aug. 25 and the Premier Level for $3,500. Over those three months the Field Level averaged $4,263 a sale against the Premier Level's $2,742.

Some of that gap comes from the card itself, since Field Level sits above Premier Level in Select's own lineup and that prestige pulls buyers and price up together. Anyone reading only PSA's counts would still call the two cards interchangeable. Buyers treated them as two different markets: a Field Level Silver sold about every 10 days this summer and a Premier Level Silver about every 30.

The slower Silver sold near $3,500 in September

The Premier Level Silver sold twice in September, for $3,410 on Sept. 5 and $3,650 on Sept. 10.⁶ Both came in well above its $2,742 average from the summer. PSA counted 130 copies in PSA 10 in August and still counted 130 on Oct. 18.⁷

If you own one, price it off those two September sales and expect to wait about a month for the next buyer.

The most common Mahomes has the most sales

Mahomes's 2017 Prizm Silver rookie has more than seven times the PSA 10 copies of either Select Silver, with 987 as of Oct. 18.⁷ It sold 36 times from July 21 to Oct. 19, about once every two and a half days.⁶

Those 36 sales added up to about $272,000, with the card selling around $7,700. The Premier Level Silver's three sales over the same stretch came to about $10,600.

The same order holds down the list. Mahomes's base Select Premier Level rookie has 621 copies in PSA 10 and sold 14 times over the same stretch. His base Field Level card has 134 copies and sold three times.

Brand explains part of that. Collectors want Mahomes's 2017 Prizm before any other Mahomes rookie because Prizm is the defining modern football rookie brand. That demand is what keeps it trading every few days.

The market pays for identity in other corners of the hobby. A jersey swatch with documented game use sells for many times what anonymous cloth sells for.

Float is the supply that trades

Population counts every graded copy. Some sit in collections that will never sell, some owners have no plans to sell, and some copies come back to market again and again. Stock traders separate shares outstanding from the float that trades, but card investors have no number like that.

A low float can push a price up because few owners will part with a copy. It can also leave you holding a card nobody is bidding on, where one determined buyer sets a record the next sale never confirms.

A low population alone isn't a reason to buy. Josh Allen's 2018 Optic Orange /199 has just 47 copies in PSA 10.⁷ The Allen Orange sold once, at $2,400.⁸ That sale came this summer by Card Ladder's count. The one before it in our records was $2,090 on Dec. 15, 2025.⁶

A last sale is only as good as the buyers behind it

Every one of the Mahomes Prizm's 36 sales since July 21 landed between $6,702 and $8,155.⁶ Its $8,000 sale on Oct. 18 is close to what the next seller can expect.

The gap widens as cards get rarer. Some high-end cards go years between sales. A recorded price can be entirely legitimate and still say little about what the next seller would get.

Cards need a spread measure

A stock shows its liquidity in the order book. A $999 bid against a $1,000 ask is a liquid market. Widen it to an $800 bid against a $1,200 ask. That gap is what a round trip costs you before the card has moved at all.

Cards have no order book. They trade through auctions, fixed-price listings, private offers, dealers, shows and several marketplaces at once. No venue publishes what buyers are bidding against what sellers are asking. The closest substitute is how tightly recent sales cluster, once the market's direction is accounted for.

From July 21 to Oct. 19 the Mahomes Prizm's sales stayed within 19% of its average price. The Allen Optic Holo's sales spread across 48% of its average.⁶

A tight range can also come from too few sales. Two September sales of the Premier Level Silver landed just $240 apart. I'd trust the Prizm's wider range more, because it rests on 36 sales.

Five numbers that tell you how easy a card is to sell

1. Transaction frequency. How often the same card in the same grade sells. Days between sales beats the date of the last sale.
2. Dollar volume. 50 sales at $50 and 50 sales at $5,000 are the same count with different money behind them. Trailing 90-day and 12-month dollar volume belong beside the count.
3. Execution dispersion. How tightly sales cluster once the market's direction is accounted for. Wide unexplained gaps mean the next sale is a guess.
4. Market depth. How many copies are offered near fair value, across how many sellers and marketplaces. A sales history does not carry this.
5. Float activity. Sales against population: This metric describes circulation at different scales.

These five numbers don't have to collapse into one score. Put them beside the population count and let each buyer weight them.

How the premium should apply

More trading doesn't raise a card's price in step. Financial markets don't price liquidity that way either. The usable form is a discount or premium on like-for-like value. A card with a deep sale history, a narrow spread and several active sellers earns a higher multiple. A card that trades twice a year takes a discount, because part of its stated value disappears when the owner tries to sell.

I want to measure that adjustment with our sales records. The test holds population, grade, product tier and player demand constant, then checks whether the faster-trading cards sell at higher multiples or hold their value better in a downturn.

What I would own

1. Canonical cards with deep sale histories. Mahomes's 2017 Prizm Silver in PSA 10 is one. Its 987 copies look like a weakness next to a numbered parallel, but 36 sales in 90 days give it a real price.
2. Scarce cards that still turn over. The Select Field Level Silver #247 is the shape I want. Its 137 PSA 10 copies sold nine times this summer, about once every 10 days.
3. Cards whose trading is growing. Rising sale counts, more marketplaces carrying the card and a tightening price range are early signs the market is adopting it, often before the price moves.

I would be slower on cards whose whole case is a low population and a thin sales record. Tightly held cards can move hard when demand arrives, but until it does, the last sale is one data point. Yesterday's price is not today's price.

Collectors count supply and stop there

Collectors can tell you Josh Allen's Optic Orange is numbered /199 and that 47 copies sit in PSA 10. They'll still price it from the last sale, even when that sale was months ago.

The same problem runs through Pokémon, Magic, Marvel, One Piece and Lorcana, where print runs and populations get quoted the same way. Supply in those markets isn't fixed either. We covered that in Nobody Is Running Out of Charizards. A card with broad recognition and steady sales has a different market from an equally scarce card that rarely changes hands.

Before you pay up for a low population, count the card's sales over the last 90 days. If it sells every few days like the Mahomes Prizm, you can sell it next month near the last price. If it sold once all summer like the Allen Orange, bid below the last sale, because you may wait months for the next buyer.