A non-fungible token (NFT) marketplace has introduced policies to ban insider trading, after an executive at the company was discovered to be buying artworks shortly before they were promoted on the site’s front page. OpenSea, one of the leading sites for trading the digital assets, will now prevent team members buying or selling from featured collections and from using confidential information to trade NFTs. Neither practice was previously banned. “Yesterday we learned that one of our employees purchased items that they knew were set to display on our front page before they appeared there publicly,” said Devin Finzer, the co-founder and chief executive of the site. “This is incredibly disappointing. We want to be clear that this behaviour does not represent our values as a team. We are taking this very seriously and are conducting an immediate and thorough third-party review of this incident so that we have a full understanding of the facts and additional steps we need to take.” NFTs are digital assets whose ownership is recorded and traced using a bitcoin-style blockchain. The NFT market boomed earlier this year as celebrities including Grimes, Andy Murray and Sir Tim Berners-Lee sold collectibles and artworks using the format. But the underlying technology has questionable utility, with some dismissing the field as a purely speculative bubble. The insider trading came to light thanks to the public nature of the Ethereum blockchain, on which most NFT trades occur. Crypto traders noticed that an anonymous user was regularly buying items from the public marketplace shortly before they were promoted on the site’s front page, a prestigious slot that often brings significant interest from would-be buyers. The anonymous user would then sell the assets on, making vast sums in a matter of hours. One trade, for instance, saw an artwork called Spectrum of a Ramenification Theory bought for about £600. It was then advertised on the front page and sold on for $4,000 a few hours later. One Twitter user, ZuwuTV, linked the transactions to the public wallet of Nate Chastain, OpenSea’s head of product, demonstrating, using public records, that the profits from the trades were sent back to a wallet owned by Chastain. While some, including ZuwuTV, described the process as “insider trading”, the loosely regulated market for NFTs has few restrictions on what participants can do. Some critics argue that even that terminology demonstrates that the sector is more about speculation than creativity. “The fact that people are responding to this as insider trading shows that this is securities trading (or just gambling), not something designed to support artists,” said Anil Dash, the chief executive of the software company Glitch. “There are no similar public statements when artists get ripped off on the platform. “If Etsy employees bought featured products from creators on their platform (or Patreon or Kickstarter workers backed new creators etc) that’d be great! Nobody would balk. Because they’d be supporting their goal,” Dash added.