Squid Game Coin, a digital token based on the popular Netflix original Korean drama series of the same name, collapsed to zero on Monday after its creators took off with the approximately 2.5 billion won ($2.13 million) invested in the coin, according to news reports.

The crypto coin once surged to as high as 3.4 million won before its unexpected but eventual collapse Monday, according to Coin Market Cap, a global cryptocurrency tracker. Ten minutes after it reached its peak, the cash invested in the tokens was suddenly liquidated by its creators. Their whereabouts are unknown, it added.

Labeling the case as an apparent “rug pull” scam, experts in South Korea said investors should have checked whether the crypto was legit for investment.

“Squid Game Coin, taking the form of a play-to-earn coin, lured many users by giving them opportunities to participate in online games inspired by the program. Also it is a ‘meme coin’ that makes investors think they are ‘on trend’ if they purchase or sell the crypto,” said Hong Sung-il, a senior researcher at Korea Economic Research Institute.

“Investors should keep in mind that the crypto market is extremely volatile. Rather than just following the investment trend, they need to look into the documents released by the crypto project that gives technical information before making an investment,” Hong said.

“Meme coins” refer to cryptocurrencies or tokens that draw investors with internet memes, jokes and images shared online, rather than use cases or other conventional investment reasons.

Amid the intensifying meme coin craze, Squid Game Coin lured investors by piggybacking on the hype surrounding the TV drama without consent from Netflix, which holds the copyright for the series, for usage of the name or the games. Army Coin, a crypto named after the global fan club of K-pop boy band BTS, also infringes on the boy band’s copyright. BTS’ agency Hybe said earlier that it has nothing to do with the virtual coin and is considering legal action.

Market insiders have warned that money invested in Squid Game Coin appears to be nonrefundable, and if crypto creators liquidate the entire coin and vanish, investors are liable to lose their money.

Launched on Oct. 26, the crypto project announced that investors could play an online version of “Squid Game” in November and the final winner would receive an unspecified bonus that depended on the number of investors playing in the game. The scam has now dashed hopes of the investors who had been looking forward to playing the games featured in the drama series, in which players risk their lives for a 45.6 billion won prize.