> For the complete documentation index, see [llms.txt](https://sup-bears.gitbook.io/sup-bears/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://sup-bears.gitbook.io/sup-bears/erc404.md).

# ERC404

What is ERC 404?

<figure><img src="https://1346423061-files.gitbook.io/~/files/v0/b/gitbook-x-prod.appspot.com/o/spaces%2F0E9WYaIR5ao1EneohKfn%2Fuploads%2Fn68V1HZ5VOTqXAZZeh19%2Fphoto_2024-02-14_00-57-39.jpg?alt=media&amp;token=7026d66d-c469-479f-8ed3-f7e7a381be9d" alt=""><figcaption><p><em>Visual Explainer of ERC404 (Tecnology Used by Sup Bears)</em></p></figcaption></figure>

### What is ERC-404?

ERC-404 is a new token standard for digital assets on the Ethereum blockchain developed by pseudonymous creators "ctrl" and "Acme."\
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Token standards are formal sets of rules and protocols that determine the behavior of tokens on blockchain networks such as Ethereum.

The ERC-404 token standard combines features of ERC-20 and ERC-721, enabling the creation of "semi-fungible" tokens that employ features from fungible and non-fungible tokens.\
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**How does ERC-404 work?**

NFTs are non-fungible, meaning that they are unique and indivisible; you can't own fractions of an NFT.

ERC-404 circumvents this limitation by using token mint and burn mechanics to enable fractional transfers of an NFT.

Issued tokens are linked to an NFT. If you buy a full token, the linked NFT is minted to your wallet. If you sell a fraction of the token, the linked NFT is burned. If a wallet holding fractions of a token purchases enough fractions to hold a complete token, a new NFT is minted automatically.

### What's so special about it?

The ERC-404 token standard enables native fractionalization of NFTs, creating new primitives and new mechanics built atop them. This, in turn, allows for experimentation with NFTs and the trading of them.