Pokémon cards have been many things a childhood hobby, a playground currency, a cartoon tie-in. Now, they are an investment vehicle outperforming the stock market, drawing in crypto millionaires, and driving scenes of near-stampedes at toy stores across Britain and the United States.

Since 2020, Pokémon card prices have risen 1,350%, according to an index compiled by Collectors, which owns grading agency Professional Sports Authenticator (PSA). Reportedly, over the longer stretch from 2004 to 2020, prices climbed 282% a fraction of the recent surge.

The Pokémon Company has since capitalised on that nostalgia by releasing sets featuring original late-90s characters. Stephanie Farnsworth, a lecturer in media and communications at the University of Sunderland, told CNBC this amounts to "a Pokémon renaissance" one the company's 30th anniversary products this year have only amplified.

`In February, influencer Logan Paul sold a rare Pikachu Illustrator card for more than $16 million having bought it for just over $5 million in 2021.

Roy Raftery, a trading card expert at London auction house Stanley Gibbons Baldwin's, told CNBC that the majority of his high-end clients are people who made money in cryptocurrency and are now cycling it into Pokémon cards.

"People tell me they've got nothing else to do with it," he said. Market watchers who spoke to CNBC noted that crypto-affiliated accounts on social media discuss card prices in the same language used for stocks debating dips and whether the latest drop is just a correction.

Raftery told that most buyers at his firm are not genuine collectors but people seeking high-end alternative assets, or global businesses buying vintage card stock specifically to resell at a profit.

Selling out within seconds, automated software allows scalpers to clear out their online stock before genuine buyers can reach checkout stage. An official release from the Pokémon Centre website selling for just £54.99 is regularly listed on eBay for well above £300.

David Bellinger, senior equity analyst at Mizuho, told that the market has moved "at such a torrid and quick pace" and carries "a little bit of a frothy bubbly aspect." Yet he also pointed to a stubborn foundation of genuine collectors people attending local card shows, completing sets, with no interest in flipping for profit that may provide a floor if speculative money eventually exits.