Definition
Multi-outcome market
A prediction market with more than two mutually exclusive outcomes.
Multi-outcome market
A multi-outcome market is a prediction market with more than two mutually exclusive outcomes. Each outcome is represented by its own CTF outcome token and, at fair value, the sum of all outcome prices equals $1.00.
In context
On Polymarket, multi-outcome markets use the Gnosis Conditional Token Framework (CTF). Each outcome is an ERC-1155 token you can split, merge, trade, and redeem. Because the outcomes are mutually exclusive, their fair-market prices should add to $1.00; when they do not, an intra-market combinatorial arbitrage opportunity exists. Combinatorial arbitrage involves buying the complete set of cheapest best-ask prices (one share in every outcome) for less than $1.00, then holding the complete set until resolution or using CTF operations to lock value. Note the risks: resolution disputes via UMA, slippage and partial fills on the CLOB, taker fees, and settlement timing.
How you’ll see it on Polymarket
- Market pages show each outcome’s best bid and best ask, plus the market’s midpoint.
- The Gamma API and CLOB market feeds expose per-outcome prices and order books.
- Tick size and taker fees still apply; when outcomes approach extremes the tick size may tighten.
See also
- /glossary/binary-market