NegRisk

NegRisk is Polymarket's grouping of mutually exclusive outcomes under one market, where exactly one outcome wins. A market with several candidates, where only one can be the answer, is a NegRisk market, and it uses a different exchange contract from an ordinary two-sided Polymarket question.

Why the odds do not add up​

Each outcome in a NegRisk market trades in a separate order book, against whoever happens to be buying and selling that outcome. Someone with a strong view on one candidate pushes that book without touching any other, and nothing in the exchange mechanism forces the books into agreement. So the Yes prices, which in principle should sum to one dollar because precisely one Yes share will pay out, frequently sum to something like one dollar and three cents, or ninety-six cents. The gap is not a display bug and it is not free money; closing it costs fees and depth. The full explanation is Why don't prediction market odds add up to 100%?

How BT365 uses it​

BT365's Polymarket integration recognises NegRisk markets and routes their orders to the NegRisk exchange contract. The platform's prediction-market overview is at prediction markets on BT365.

BT365 is not available in every jurisdiction, and nothing on this page is investment advice. Trading prediction markets carries risk of loss.