USDC
USD Coin — the dollar-pegged stablecoin used as the sole deposit, collateral, and settlement currency on Polymarket.
Definition
USDC (USD Coin) is a fully-reserved dollar-pegged stablecoin issued by Circle. On Polymarket, all collateral is held in USDC on Polygon. Buying outcome tokens costs USDC; winning positions redeem for USDC. The 1:1 peg to USD makes USDC suitable for prediction market collateral because the value is stable over the short windows (minutes to days) that most markets span.
In practice
Bot operators deposit USDC to their Polymarket proxy wallet before running in live mode. The balance is visible via node tools/trade.js balance. All bot PnL calculations are denominated in USDC. The key operational risk is depositing Polygon-native USDC rather than Ethereum mainnet USDC — these are different tokens requiring a bridge transfer. Always verify the deposit address and network before funding a live bot wallet. Minimum positions on Polymarket require at least 5 shares, so a minimum usable deposit is typically $5-$10 USDC to allow meaningful position sizing.