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Professor Oak's New Theory
HeartGold SoulSilver · #101/123
Professor Oak's New Theory (101/123), the Uncommon from HeartGold SoulSilver, has an estimated ungraded market price of about $0.80.
As of September 13, 2026 · tracked daily by Riffle · estimates, not financial advice · how these numbers work
The modeled fair value of this card, with a confidence grade: what it should trade at, not just what it lists at. Part of Riffle premium, alongside price history and the full graded ladder.
About Professor Oak's New Theory
Professor Oak's New Theory is a Uncommon (101/123) from the Pokémon HeartGold SoulSilver set, released February 10, 2010. Ungraded copies currently trade at an estimated market price of under $1. The artwork is by Ken Sugimori. Riffle tracks its market price daily; graded (PSA) comps and full price history are available with Riffle.
Other versions of Professor Oak's New Theory
Professor Oak's New Theory appears on 2 different cards across the sets Riffle tracks, at very different values. This page covers #101/123 from HeartGold SoulSilver; the collector number printed at the bottom of the card tells them apart.
FAQ
How much is Professor Oak's New Theory (101/123) worth?
Professor Oak's New Theory (101/123), the Uncommon from HeartGold SoulSilver, has an estimated ungraded market price of about $0.80. Note: 1 other card named Professor Oak's New Theory exists across the sets Riffle tracks, at very different values; check the collector number.
Which Professor Oak's New Theory card is this, and how do I tell the versions apart?
This page covers Professor Oak's New Theory (101/123), the Uncommon (about under $1) from HeartGold SoulSilver.
The other version: #83/95 from Call of Legends (Uncommon, about $0.80–$1).
The collector number printed at the bottom of the card is the reliable way to tell them apart.
Is Professor Oak's New Theory (101/123) rare?
Professor Oak's New Theory (101/123) is a Uncommon. PSA has graded 18 copies to date, so graded supply is measurable and growing.
More from HeartGold SoulSilver
PSA population & gem rate
From the PSA population census, captured monthly by Riffle. Grade-by-grade population and pop-over-time appear with Riffle premium.
- under $1 is the middle 80% of clean market activity, not the cheapest listing and not the most hopeful one.
- The band spans about ±13% around its midpoint: a moderate spread.
- Sampled daily since August 25, 2026, current as of September 13, 2026.
When the data thins, the band widens and says so, it never fakes precision. Exact source prices are part of Riffle premium; the band is Riffle’s own figure to publish. How these numbers work →