What is the Polymarket CLOB?

💡 Definition: Polymarket CLOB

The Polymarket CLOB (Central Limit Order Book) is a hybrid high-performance exchange architecture. It matches bids and asks off-chain with sub-millisecond latency while settling transactions on-chain via Polygon smart contracts using cryptographic EIP-712 order signatures.

0% Maker Fees vs Taker Fees

Unlike automated market maker (AMM) pools that incur high liquidity provider slippage, the Polymarket CLOB incentivizes liquidity makers with 0% trading fees on passive limit orders. Our bot posts passive limit orders exclusively, qualifying for zero maker fees and earning the complete spread on each 15-minute complete-set turn.

Cryptographic EIP-712 Order Structure

Each order sent to the CLOB consists of a typed data structure signed locally by your private key:

  • Maker: Your public Polygon wallet address.
  • Taker: Null address (allowing open matching).
  • TokenId: Specific conditional token outcome identifier (Up or Down).
  • MakerAmount / TakerAmount: Order size and price ratio.
  • Salt & Expiration: Prevents replay attacks and ensures automatic order expiry.