He had a message for his six million followers that he was all in Dink Doink.

Dink Doink investors would receive shares of a cartoon character if it ever appeared in a TV show or movie. Mr. Paul praised Dink Doink on social media and in a Telegram chat before endorsing it again on his show.

The price of Dink Doink had plummeted by mid-July, and Mr. Paul was facing an online backlash. He failed to mention that he and the project's creator were friends, and that they came up with the idea for the coin together. He received a lot of Dink Doink coins when it launched.

Mr. Paul said in an interview that he didn't know what went wrong.

The celebrity marketers who sell virtual currencies to the public have come under scrutiny after the collapse of the price of the coins. Over the last year, the actor Matt Damon and the comedian Larry David have starred in high-profile TV commercials for digital assets. The ads were tied to mainstream companies with hundreds of millions of dollars in revenue.

There are undisclosed conflicts of interest and exaggerated claims about skyrocketing profits in the form of a far seedier form of crypto promotion. Kim Kardashian and Floyd Mayweather have made millions of dollars endorsing specific and often dubiouscryptocurrencies, urging fans to buy obscure coins that quickly crashed in value, or shilling little-known collections of nonfungible token, the unique digital files known as NFTs.

Mr. Paul has admitted that he failed to disclose personal or financial ties to projects advertised on his feeds, a potential violation of federal marketing regulations. A series of ventures backed by celebrities had crashed, hurting amateur traders and prompting lawsuits that could force celebrities to compensate investors for their losses.

John Reed Stark is a former chief of the internet enforcement branch at the Securities and Exchange Commission.

Dogecoin, a joke currency based on a meme, was turned into one of the most valuable cryptocurrencies after a brief online hype.

There are some people in the world who have large followings on social media and broadcast market tips. Ms.Kardashian is facing a lawsuit from investors over her marketing of an obscurecryptocurrencies.

The amount of money paid to a promoter can be very high. According to a presentation reviewed by The New York Times, an NFT project called Hive Investments has been offering large sums of money to people who are influential.

Jordan Belfort was offered $250,000 to change his NFT profile picture, which was used in the movie The Wolf of Wall Street. Mr. Belfort turned down the offer.

ImageJordan Belfort, center, at home in Miami Beach, with attendees of a crypto class. Mr. Belfort, a former stockbroker, has rebranded himself as a crypto guru.
Jordan Belfort, center, at home in Miami Beach, with attendees of a crypto class. Mr. Belfort, a former stockbroker, has rebranded himself as a crypto guru.Credit...Scott McIntyre for The New York Times

Mr. Belfort's business partner said they don't want to be a part of things that separate people from their money.

There is a legal gray area. Federal law requires people to publicly disclose payments for promotions. S.E.C. charged Mr. Mayweather with failing to properly disclose his compensation for marketing initial coin offerings, the equivalent of an initial public offering on Wall Street. The rule he broke only applies to securities, like stock in a company, and it's unclear which products meet that legal standard.

The Federal Trade Commission requires marketers of all kinds to disclose when they have a financial stake in the projects they endorse.

David Klein is a lawyer in New York who specializes in marketing rules. Otherwise, the regulators will call.

Celebs who disclose payments have found themselves in legal trouble. In August of last year, Ms.Kardashian endorsed the platform, but at the bottom of her post, she said, "This is not a recommendation to buy or sell ether."

The promotion led to a surge of trading, but the price soon collapsed. The project's creators and other people, including Mr. Mayweather and the former basketball star Paul Pierce, are accused of faking their control over the project.

According to the lawsuit, Mr. Pierce received more than 15 trillion ether max token in exchange for endorsing the coin. The lawsuit did not mention a business relationship with the token's creators. The lawsuit claimed that Mr. Pierce profited from encouraging fans to buy the token, before selling his holdings at a higher price.

The allegations in the suit are not merited, said a lawyer for Ms.Kardashian.

Kim Kardashian is facing a lawsuit from investors over her marketing of an obscure cryptocurrency, EthereumMax.Credit...Hunter Abrams for The New York Times

As the price ofCryptocurrencies has crashed, investors have turned to lower-profile social media stars who post sponsored content. One of the most well-known and well-liked people in the digital space is Ben Armstrong, who runs a YouTube channel where he discusses market trends and talks about his favorite projects. After his price sheet was made public, he discontinued the service he used to provide.

Some of the projects promoted by Mr. Armstrong encountered problems. He considered himself a victim in those cases.

He said that they are preying on the novice crypto influencer who is trying to figure out what they should and shouldn't be doing.

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There is a virtual currency called th digital currency called th digital currency is called th digital currency is called th digital currency is called th digital currency is called th digital currency is called th digital currency is called th digital currency is called th digital currency is There is a digital token that can be sent anywhere in the world. This form of digital currency is stored and moved on a payment network.

There is a system for storing data called the Blockchain. A database maintained communally and that reliably stores digital information can be found on a blockchain. Non-currency-based companies and governments are trying to use the same technology that was used to store all of the Bitcoins.

It is possible to pay with corp coin. The first major company to list its shares on a U.S. stock exchange is Coinbase, a platform that allows people and companies to buy and sell various digital currencies.

Web3. The idea of a new kind of internet service that is built using a new kind of token is what some technologists call it.

They are called DAOs. A DAO is an organizational structure that is built with the use of the internet's technology. Investing in start-ups, managing a stable coin or buying NFTs are examples of the common purpose of a DAO.

Mr. Paul rose to fame as a video blogger and an occasional actor, but he was reprimanded by YouTube for publishing footage of a dead body he found in a Japanese forest. He has used his internet fame to launch a line of energy drinks.

Mr. Paul was interested in the market for NFTs. He acknowledged in a recent interview that he was still learning how to navigate the market, even as he tried to profit from the technology.

Mr. Paul was involved in some of the initial ideas for the Dink Doink project. Jake gave Mr. Paul 2.5 percent of the token that was initially issued.

In June of last year, Mr. Paul called it one of the most ridiculous cryptocurrencies he had ever encountered, and shared a video of a cartoon character singing sexually explicit lyrics. He praised Dink Doink in a shaky cam video on Telegram.

The campaign was a flop and Mr. Paul was pilloried. The price of Dink Doink fell even further in value over the summer. Mr. Paul said he had never profited from the project. He regretted promoting the coin without revealing his financial stake.

After Dink Doink's crash, Mr. Paul started an NFT collection that featured stock images of animals. The staff who helped run the project were blamed by Mr. Paul. He is working with a new team on a venture called Liquid Marketplace, which uses a new type of technology to let investors buy fractions of physical objects.

“I definitely didn’t act as responsibly as I should have,” Mr. Paul said. Credit...Sinna Nasseri for The New York Times

Mr. Paul said that the recent crash will weed out the weak. He said that it made him rethink some of his promotions, after he lost $750,000.

I don't want anyone to feel like they've been screwed because of anything I've done.

Mr. Paul knows what it's like to lose a deal. He fought Mr. Mayweather in Las Vegas last year in a boxing exhibition that drew more than one million pay-per-view customers. Mr. Paul claimed that Mr. Floyd hadn't fully compensated him for the fight. Mr. Floyd replied that he was happy with the biggest pay day of his life.

Fans were encouraged to buy tickets using the cryptocurrencies.

Kitty Bennett was involved in research.