Part of the fun of collecting active players is to root for them to succeed and, it is thought, the better they do, the better you do.
But playing fantasy basketball with modern cards has proven to be a flawed model.
The most recent example?
Jayson Tatum.
Three weeks after the Boston Celtics won the title, most of Tatum’s cards — at low, medium and high-end — are mostly down significantly.
At the high-end, there are three exact comps where the same card sold before and after the title.
A collector bought a 2017 National Treasures RPA in a BGS 9.5/Auto 10 out of 5 for $84,083 on Alt on March 24.
This weekend, that card went for $68,340 at Alt (which lists the sale as "pending"), an 18.7 percent decline and a loss of $152.84 per day over the hold period (103 days).
Another collector bought a 2017 National Treasures, numbered 13/99 for $30,000 at PWCC on Dec. 21. That card sold June 20, three days after the Celtics won it, at PWCC for $16,500.
That’s a whopping drop of 45 percent of the initial value and a $71.18 per day loss while held (182 days).
A 2017 National Treasures First Off The Line, numbered 6/15, initially sold for $40,800 on March 21 at PWCC. A June 20 sale yielded $25,800, a 36.7 percent drop and a loss of $164.84 per day while held (91 days).
Not an exact comp, with some expected variance based on patches, but a 2017 National Treasures RPA out of 99 (73/99) — given a PSA 10, Auto 10, sold for $43,200 on June 20. The last PSA 10, Auto 10 of the same card, with a better patch, sold for $126,880 in Dec. 2023 at Goldin, a drop of 66 percent.
At the mid-range, the 2017 Tatum Silver Prizm in a PSA 10, is holding up. Selling in the mid-$900s in June, one sold Sunday night at PWCC for $1,020.
At the lower range, it has not been good news for collectors. The 2017 base Prizm in a PSA 10, which has a population of 6,364, had a high of $200 over the last six months, but is now selling in the $100 range (down 50 percent), rebounding from a post-title low of $85 on June 25.
A 2017 Donruss Optic Base in a PSA 10 cost $118 on June 17, the day before Tatum and the Celtics prevailed, according to Sports Card Investor data. Last night, one sold for $84, a drop of nearly 29 percent.
So why the drop? To state the obvious, collectors think they are selling into the title win, so there’s a flooding of the market. Second, there’s an assumption that a card’s present value correlates to the status of the star in the moment, which, as we’ve found with Patrick Mahomes cards after Super Bowl wins, hasn’t proven to be true.
Was there a title baked in to Jayson Tatum’s cards already? Without a doubt.
Darren Rovell is the founder of cllct.com and one of the country's leading reporters on the collectible market. He previously worked for ESPN, CNBC and The Action Network.