Where prices come from

Live prices

Prices come from Polymarket's public order book. A chance of 58% is the midpoint between the best buy and sell price for that outcome. Pages refresh prices every 10 to 30 seconds; the 5-minute rounds every few seconds.

Recording a price

When a call, combo or challenge is made, the server reads the order book at that moment and refuses if it can't. It never trusts a price sent from the browser, and never falls back to a delayed price feed for anything that goes on a record.

Sample markets

If Polymarket can't be reached, pages show a few clearly labelled sample markets so nothing breaks, and calls are paused until live prices are back.