Polymarket, a prediction market platform, will undergo a significant upgrade on April 28, 2026, at 11:00 UTC, pausing trading for one hour. The upgrade will introduce the CTF Exchange V2 smart contract, revamp the order book system, and migrate collateral from USDC.e to Polymarket USD (pUSD). Users are advised that existing order books will be cleared, necessitating new orders post-upgrade. A one-time authorization will be required for first trades, but no further action is needed from most users. Transactions will continue to settle in native USDC. The CTFv2 contract has been audited by Cantina and Quantstamp, ensuring security and reliability. Additionally, Cantina has launched a bug bounty program to further enhance the platform's robustness.