Ethereum Name Service, or ENS, .eth domains ranging from 0000 to 9999 have recently been causing a stir among nonfungible token (NFT) investors, speculators and enthusiasts alike. Even though three- and four-digit names have been around for years, the number of people registering for ENS domains and purchasing these digit number names on secondary markets over the past week has significantly affected the market’s trading volume.

According to a Dune Analytics dashboard for ENS, the spike in sales began on April 21, and the number of eth. name registrations have since jumped from 2,721 to 21,188 by Thursday. Over the last seven-day period, ENS domains’ trading volume on OpenSea climbed by 3,333% to 2,613 Ether (ETH), or $7.3 million at the time of writing. The last 48 hours have seen the most ENS NFT trading in the secondary market, with the most expensive domain so far, “555.eth,” selling for 55.5 ETH, or $156,821.91 on Thursday.

Each ENS web name is an NFT that is minted and sold like any other nonfungible token. These decentralized domains that end in .eth can act like Ethereum wallet addresses, cryptographic hashes and website URLs. Since decentralized applications (DApps), wallets, exchanges and marketplaces increasingly support NFT usernames, whether from ENS or from competitors like Unstoppable Domains, Web3 users are embracing the value that can be tied to a digital identity.

Holders who have scooped up ENS names from 0-9999 have formed an exclusive Discord channel called the 10kClub. At the time of writing, nearly 4,000 ENS holders had joined this social club. Members even created a refrain that was continuously posted throughout the Discord chat stating, “I AM MY NUMBERS AND MY NUMBERS ARE ME.” According to the 10kClub Twitter page, there is no roadmap. 

Consequentially, the website has been crashing this past week and leading users to a 404 error page because the website couldn’t be found on the server. On Thursday, the ENS team tweeted multiple times that they are working to resolve the issue.

Related: The concept and future of decentralized Web3 domain names

Not just individuals but also major brands and corporations have recently registered their names with Ethereum Name Service such as Puma and Budweiser.