Most people, by now, have probably heard of Bitcoin and Ethereum (which have been chugging along for years) but 2021 has been the year of DeFi—or decentralized finance.

DeFi doesn’t have a formal definition, but it typically includes the use of the blockchain to borrow and lend using auction markets. The chance to make some cash comes, in part, because the blockchain eliminates the need for traditional financial intermediaries, with their fees and associated regulations.

According to Vice, a common trait among many DeFi tokens is that they shamelessly promise investors a huge return. They often rely on complex schemes in an effort to pump up their value. For example, SafeMoon, a DeFi token promoted by popular influencers, taxes sellers and distributes a portion to holders. In the past year, people have won big, then lost it all, as cryptocurrencies have gone viral and then crashed.

But that’s not stopping anyone from trying their hand at striking it rich—either by creating their own coins or stealing the funds outright. According to CipherTrace’s May 2021 crypto crime report, $156 million was stolen via DeFi-related hacks so far in 2021.

And as much as the potential excites some people, others are getting scared by the notorious volatility. Just look at Elon Musk’s tweets about cryptocurrency, which often send prices soaring or plummeting. On Sunday, bitcoin saw a boost after he announced that Tesla would resume bitcoin transactions once it confirms there is reasonable clean energy usage by miners.

Billionaire investor Mark Cuban acknowledges the risks and that there are technicalities to sort out with all of this technology but still says that “this approach is the future of personal banking.” In a blog post earlier this week, he said “banks should be scared.”

However, Dutch economic officials have predicted the “ultimate collapse of the crypto bubble.” They have urged the government to ban bitcoin and other cryptocurrencies immediately.