ERC-20-TOKEN

Ethereum fungible token standard ERC-20.

Definition

ERC-20 mandatory functions: totalSupply(), balanceOf(address), transfer(to, amount), transferFrom(from, to, amount), approve(spender, amount), allowance(owner, spender). Events: Transfer, Approval. Optional functions: name(), symbol(), decimals() (typically 18). Examples: USDC (~$30 billion market cap), USDT (~$120B), DAI (~$5B), UNI, LINK, AAVE, COMP, etc. Risks: reentrancy attacks (mitigated by OpenZeppelin libraries), approval frontrunning (EIP-2612 permit signatures).

Origin

ERC-20 proposed by Fabian Vogelsteller (Ethereum Foundation) November 2015 ; EIP-20 standard finalised September 2017 ; ~700000+ deployed ERC-20 tokens 2024.

Example in context

USDC stablecoin issued by Circle/Centre Consortium is an ERC-20 token with 30 billion supply 2024 ; supports standard transfer, approve patterns ; integrated in all Ethereum DEXs and lending protocols.

Related terms

• ERC-721 NFT — non-fungible standard.