Rug pull scams "pumping up" a new project, nonfungible token (NFT) or coin to get funding. After the scammers get the money, they disappear with it. The coding for these investments prevents people from selling the bitcoin after purchase, so investors are left with a valueless investment.
It’s been happening for years. This is why you need to do extensive research before you FOMO into random alts. To be honest, it’s better to just stick with bitcoin or mainstream alts. Lots of the lesser known coins are a minefield of scams.