Polymarket is overhauling how its short-duration crypto prediction markets settle, replacing single-price snapshots with a time-weighted average price mechanism powered by Chainlink oracles. The upgrade goes live on August 7, 2026, at 00:00 UTC, and comes paired with a $1 million liquidity rewards program designed to deepen trading activity across affected markets.
The core problem being addressed is straightforward: when a market settles based on one price at one moment, anyone with enough capital can shove the price in their favor right before expiry. Polymarket’s fix is to average prices over a window of time, making that kind of last-second manipulation significantly more expensive to pull off.
How the TWAP mechanism works
The new settlement model uses what’s called a TWAP, or time-weighted average price. Instead of checking what Bitcoin or Ethereum costs at the exact second a market expires, the system will average prices across a defined window leading up to expiry.
For 5-minute markets, that window is 30 seconds. For the longer 15-minute and 4-hour markets, it stretches to 60 seconds.
