New technology is upending everything in finance, from saving to trading to making payments.

Some financial experts may think cryptocurrencies are just a big bubble, but top athletes, musicians, and socialites say otherwise. They’re backing the red-hot “initial coin offerings” that claim to revolutionize both finance and technology. Here are some noteworthy recent endorsements from unexpected crypto-enthusiasts:

Paris Hilton

Token of choice: LydianCoin

Show of support: Hilton tweeted that she was taking part in the forthcoming LydianCoin ICO. She seems genuinely enthused about the future of blockchains, big data, AI, and adtech, specifying that her tweet was “not an ad.” She also tweeted an analysis of the ICO showing that it complied with a legal benchmark for securities offerings called the Howey Test.

What’s the deal?: The coin issuer is asking for $100 million to make coupons for marketing services with its parent company, Gravity4.

Floyd Mayweather

Token of choice: Stox tokens and Hubiits

Show of support: Mayweather briefly updated his moniker from “money” to “crypto” for Hubii in an Instagram post, declaring, “You can call me Floyd ‘Crypto’ Mayweather from now on.” The boxer shares his enthusiasm for Stox.com’s ICO with Barcelona soccer star Luis Suarez.

What’s the deal? Stox.com needs $30 million for what are essentially casino chips to use in a prediction market, and Hubii seeks $50 million so writers, musicians, and filmmakers can cut out Netflix, Spotify, and YouTube and somehow still get paid.

The Game and Jessica VerSteeg

Token of choice: Paragon Coin

Show of support: Rapper The Game and former Miss Iowa and Amazing Race contestant Jessica VerSteeg have tweeted extensively, with video, about the Paragon Coin ICO.

What’s the deal? Paragon requires $100 million for a farm-to-pipe cannabis supply-chain tracking and payments system. It isn’t the only cryptocurrency that promises to reshape the cannabis industry. PotCoin sent former basketball pro Dennis Rodman to Pyongyang to spread the word about its potential for secure payments in the marijuana business.

Mike Tyson

An honorary mention for Mike Tyson, who launched a line of bitcoin ATMs in Las Vegas back in 2015, way before any of the ICO hype got started. “I’m grateful to be part of the [bitcoin] revolution,” he told trade publication CoinDesk before the launch. Bitcoin was trading for about $230 back then, or about 5% of its price today. Now that’s foresight.