// GLOSSARY

CLOB operator

The party that runs a CLOB's matching engine. On Polymarket, the operator matches signed orders off-chain and submits matched trades for on-chain settlement — a hybrid model: non-custodial settlement, but matching depends on the operator being live and honest.

On a traditional exchange like Kalshi, the exchange itself is the operator: it runs the book, matches orders, and clears trades under a regulatory framework. Polymarket's hybrid CLOB splits the roles — the operator runs off-chain matching for speed, while settlement of matched trades happens on-chain on Polygon against EIP-712-signed orders.

What the operator can and can't do

Because your order is a signed message with explicit terms, the operator generally can't fill you at a worse price than you signed for — the chain verifies the signature at settlement. What the operator does control is availability and ordering: if matching is down or degraded, you can't trade, and the sequencing of matches is in its hands. As with any venue-specific detail, check Polymarket's current docs for the exact trust model.

Practical takeaway

For API traders the operator is mostly invisible — you talk to clob.polymarket.com and it behaves like an exchange endpoint. The differences surface in failure modes and in order lifecycle details, covered in the Polymarket CLOB API guide.