Polymarket Shifts Crypto Contracts to 60-Second TWAP Settlement via Chainlink

Polymarket has updated the settlement mechanism for its short-duration crypto Up/Down markets — covering 5-minute, 15-minute, and 4-hour contracts — to use a 60-second Time-Weighted Average Price (TWAP) sourced from Chainlink, replacing the previous 30-second or snapshot-based approach as of August 14. A TWAP calculates the average asset price over a trailing one-minute window, meaning the final settlement reflects a smoothed price rather than a single instantaneous tick. This change significantly raises the cost and difficulty of price manipulation, as an attacker must now sustain a distorted price for a full minute rather than exploiting a brief wick at expiry. For traders and algorithmic systems, last-tick sniping strategies lose most of their edge, and any models calibrated to the older 30-second series will produce systematic errors until recalibrated. The shift is expected to improve overall market integrity and reduce settlement sensitivity to microstructure noise, though it also lowers responsiveness to genuine but very short-lived price moves.