Ronaldo and Binance teamed up last November on the CR7 NFT collection, with the football star telling potential investors on social media "we are going to change the NFT game and take football to the next level".
The suit claims that Ronaldo's endorsement led plaintiffs to make loss-making investments, according to the BBC.
Claimants allege that some people were led to invest in what the suit calls "unregistered securities" such as Binance's BNB token.
The footballer “promoted, assisted in, and/or actively participated in the offer and sale of unregistered securities in coordination with Binance,” says a filing.
Ronaldo knew or should have known about the unregistered crypto securities, as he has “investment experience and vast resources to obtain outside advisers,” say the claimants.
The suit also cites SEC guidance on celebrities disclosing payments for crypto promotions.
This week, Ronaldo hinted at further cooperation with Binanace, telling his hundreds of millions of social media followers that he is "cooking something up," with the company: