Cryptocurrency is on a wild ride. As bitcoin trades at over $17,000 per coin, according to CoinDesk's price index, experts debate its staying power, with high-profile investors like Jamie Dimon and Warren Buffett calling it a "fraud" and a "mirage," respectively. Meanwhile, many crypto investors fret about a bubble and fear regulators will eventually crack down. But the risks haven't stopped celebrities such as Paris Hilton, Floyd Mayweather and Jamie Foxx from getting in on the action, in some cases pretty early on. And being stars, they've often used their social media platforms to let everyone know what they're up to. (It's worth noting that if the celebrities don't disclose exactly how they're benefiting from the publicity, it could be illegal to make endorsements, according to the Securities and Exchange Commission.) From prominent bitcoin billionaires to professional athletes, here's a look at some celebrities who are publicly endorsing and/or investing in various cryptocurrencies.

Cameron and Tyler Winklevoss

Some of the most well-known people investing in the popular currency bitcoin also happen to be some of the richest. As of early December, Cameron and Tyler Winklevoss had reportedly become billionaires, thanks to the early $11 million investment they made in the speculative asset in 2013. The twins may be best known for suing Facebook founder Mark Zuckerberg in 2008 over the claim that he stole the idea for the social network from them and ending up as characters in the movie version of the story. They were awarded $65 million.

Paris Hilton

Entrepreneur and former reality TV star Paris Hilton has shown interest in the cryptocurrency market since at least 2016, the Guardian reports, citing a now-deleted Instagram post of the star with the former chief commercial officer of Ethereum. In September, Hilton also announced via Twitter that she would be participating in the initial coin offering — a controversial yet increasingly popular way that crypto start-ups can crowdsource funding — for LydianCoin, a platform that aims to combine blockchain with AI-driven marketing, according to Business Insider. Hilton appeared to distance herself from the project after domestic violence charges against Gurbasksh Chahal, CEO of LydianCoin's parent company Gravity4, came to light and resulted in possible jail time for the executive.

Floyd Mayweather

Boxer Floyd Mayweather showed his interest in cryptocurrency via Instagram on two occasions. In July, he posted a photo of himself on a private plane next to a table covered in money with the caption: "I'm gonna make a s--- t-- of money on August 2nd on the Stox.com ICO." Stox, a sister site to Invest.com, is a bitcoin prediction market product.

In August, Mayweather took to Instagram again to show his support for blockchain-based decentralized marketplace Hubii Network's ICO. Under a photo of himself, the boxer added the caption, "You can call me Floyd Crypto Mayweather from now on."

Ghostface Killah

In October, Wu Tang Clan's Ghostface Killah, also known as Dennis Coles, announced his investment in the cryptocurrency world as a co-founder of Cream Capital, a firm aiming to build a blockchain ATM network to facilitate the use of coins like Ethereum and bitcoin. At the time, the firm was gunning to raise $30 million in funding through an initial coin offering, CNBC reports. However, even those close to the company were wary of the celebrity's endorsement. "I personally think that anything that puts cryptocurrencies in front of the eyes of everyday people is a great thing for the markets overall," Brett Westbrook, chief executive at Cream Capital, told CNBC. "On the other hand, I believe it's important that celebrities know the importance of their endorsements and understand the underlying principles of blockchain technology."

Jamie Foxx