ERC-20

ERC-20

ERC-20 is the fungible token standard used on Ethereum and Ethereum-compatible chains (including Polygon). It defines a small set of functions and events that allow wallets, exchanges, and smart contracts to interact predictably with interchangeable tokens — for example, querying a balance, transferring tokens, or approving another address to spend tokens on your behalf.

In context

On Polymarket you encounter ERC-20 tokens in two primary places. USDC is an ERC-20 stablecoin that serves as the underlying asset, and pUSD is Polymarket's wrapped-USDC ERC-20 token used for trading and settlement on Polygon. Because both are ERC-20 tokens, wallets and the Polymarket Relayer can move, approve, and account for them using the same standard interfaces (approve, transferFrom, balanceOf, totalSupply, etc.).

Practical notes

• Approvals: Polymarket (via its Relayer) may request an ERC-20 approval so the exchange contract can transfer pUSD on your behalf. These approvals are gasless to the end user because Polymarket sponsors gas, but the ERC-20 mechanics remain the same.
• Composability: ERC-20 compatibility means other smart contracts and tooling can integrate with pUSD and USDC without custom adapters.
• Differences from ERC-1155: Outcome tokens on Polymarket are ERC-1155 (CTF) tokens, not ERC-20. ERC-20 tokens represent fungible currency, while ERC-1155 tokens represent conditional outcome shares.

See also

• /glossary/usdc
• /glossary/pusd