Professor Oak's New Theory

Uncommon · #101/123

Professor Oak's New Theory #101/123 (HeartGold SoulSilver) is worth about $6.99 today for a Reverse Holofoil copy, the TCGplayer market price for any condition as of 2026-10-27, flat over 30 days. Non-holo copies are $0.71. Updated 2026-10-27

This card has 2 printings (TCGplayer market, 2026-10-27): Reverse Holofoil $6.99 (this page), Normal $0.71 (on this page's chart).

price trend and all-time high: more ↓

Professor Oak's New Theory #101/123 is holding steady: $6.99 today, flat over 30 days and at its all-time high (2026-10-14), and 2.3x its low of $3.06 (2024-04-29). TCGplayer market price as of 2026-10-27, tracked daily since 2024-02-08. chart →

today's biggest Pokemon movers →most valuable Pokemon cards →

illustrated by Ken Sugimori

Price data for your app or store: API and daily history since 2024 · CSV download

$6.99

▲ 0.4% · 30d

Reverse Holofoil · TCGplayer market · daily · any condition ↗

condition prices from JustTCG listings, as of 2026-10-27

buy:TCGplayer ↗eBay ↗all marketplaces ↓

Recent sales

eBay sold ↗

every completed sale, live

new high · 2026-10-27

LOADING TAPE

WORTH GRADING?

WHERE TO BUY AND SELL

Reverse Holofoil · no eBay scan yet

TCGplayer

$4.00

lowest listing · market $6.99

buy on TCGplayer ↗

eBay · raw

no listings

no scan yet

shop active ↗ · sold ↗

eBay · PSA 10

no graded listings

no graded asks in the last scan

PSA 10 sold listings ↗

Buy-side estimate

$6.99

THIN

a patient buyer pays about $6.99 delivered, from live asks, not sales

show the work →

TCGplayer only, no eBay scan yet

TCGplayer market	$6.99	verify ↗
TCGplayer lowest ask	$4.00

Single source: TCGplayer market (no usable eBay asks in the last scan).

v2 · the full published formula →

sell to a card shop: $4.89 cash · $5.59 store credit · about 70% / 80% of market

The verdict · premium

Cards at their high after a flat month were higher 90 days later 61% of the time in our archive since 2024 (58,130 cases). That rate is mostly the 202448 to 5877 to 86marketplace fees of about 13% most short holds lose money. Use it to time a sale, not to flip.

The median move, the verdict and the grade-worthy math: try Premium free for 7 days →

GAME DATA[ + ] SHOW

CARD TYPE: Supporter
STAGE: Supporter
HP: 0
ATTACK 1: Shuffle your hand into your deck. Then, draw 6 cards.
CARD TEXT: You can play only one Supporter each turn. When you play this card, put it next to your Active Pokemon. When your turn ends, discard this card.

MORE BY KEN SUGIMORI

MORE FROM HEARTGOLD SOULSILVER

FULL SET →

Ho-Oh Legend (Top)

$258.41

Ho-Oh Legend (Bottom)

PRICE FAQ

What would a card shop pay for Professor Oak's New Theory?

Shops and show vendors commonly offer about 70% of market in cash and 80% in store credit. At today's $6.99 market price that is roughly $4.89 cash or $5.59 trade for a near-mint copy. Selling it yourself on TCGplayer or eBay nets more after fees; see the seller-net answer below.

What is Professor Oak's New Theory (HeartGold SoulSilver) worth today?

Professor Oak's New Theory [Reverse Holofoil] has a TCGplayer market price of $6.99 as of 2026-10-27. Non-holo copies are $0.71.

Is Professor Oak's New Theory going up or down in price?

What is the all-time high price for Professor Oak's New Theory?

In TickerMint's daily data (since February 2024), the TCGplayer market price for Professor Oak's New Theory [Reverse Holofoil] (all conditions) peaked at $6.99 (2026-10-14) and bottomed at $3.06 (2024-04-29).

how these numbers are computed →

DISCUSSION

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