Where prices come from

Every price on Backd is Polymarket's order book, read live. Nothing is made up and nothing is trusted from the browser.

Live prices

A chance of 58% is the midpoint between the best buy and sell price for that outcome. Pages refresh prices on a short timer. Live match centres and up-or-down rounds refresh every few seconds.

Recording a price

When you back a call, the server reads the order book at that moment and refuses if it can't. It never trusts a price sent from the browser. The call is recorded at the price your order actually filled at.

When the price moves

The midpoint you see and the price your order fills at can differ, because backing a side takes the best price on offer. The order is all or nothing at up to 3% over the price shown (cash-outs at no less than 3% under), so that is the most the book can move against you before nothing fills. The call is recorded at the price that actually filled. On thin books a large stake may not fill at all. Try smaller.

Sample markets

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