Pokémon TCG · HeartGold & SoulSilver

Professor Oak's New Theory

Name: Professor Oak's New Theory - HeartGold & SoulSilver #101
Brand: Pokémon TCG

HeartGold & SoulSilver · #101 · Uncommon

Illustrated by Ken Sugimori

Market price, Normal $0.72 As of Oct 20, 2026 Common / bulk

Not much on its own, around $0.72. It is a common, widely-printed card.

Lowest listing: $0.25 on Oct 20, 2026, any condition
Reverse Holofoil: $6.99 market price, lowest listing $4.00 on Oct 20, 2026

This market price has barely changed across the days we saved. It only updates when a copy sells, so it may rest on few recent sales.

Every saved price

Date	Market price
May 30, 2026	$0.89
Jun 2, 2026	$0.90
Jun 5, 2026	$0.90
Jun 8, 2026	$0.90
Jun 11, 2026	$0.90
Jun 14, 2026	$0.90
Jun 17, 2026	$0.90
Jun 20, 2026	$0.90
Jun 23, 2026	$0.90
Jun 26, 2026	$0.90
Jun 29, 2026	$0.90
Jul 2, 2026	$0.93
Jul 5, 2026	$0.93
Jul 8, 2026	$0.92
Jul 11, 2026	$0.97
Jul 13, 2026	$0.92
Oct 20, 2026	$0.72

#105 by market price in HeartGold & SoulSilver on Oct 20, 2026 Ungraded. The market price is an average of recent online sales. We do not know how many sales it is based on. How card values work →

Supertype: Trainer
Subtypes: Supporter
Set: HeartGold & SoulSilver
Series: HeartGold & SoulSilver
Released: 2010/02/10
Card number: 101