Glossary

A working glossary of every term you need to read, trade, or talk about prediction markets — from YES share to CFTC to UMA oracle.

Updated

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Glossary

Binary market

A market whose only possible outcomes are YES or NO. The default and most common contract type.

Glossary

Dispute

A formal challenge to an oracle's proposed market outcome, opened during a defined dispute window.

Glossary

Oracle

The party — human, on-chain, or hybrid — that reads the resolution source and posts the official market outcome.

Glossary

Expiration

The date and time when a market closes to trading and begins the resolution process.

Glossary

Open interest

The total dollar value of contracts currently held by traders that have not yet settled.

Glossary

Volume

Total notional value of shares traded over a given period, usually 24 hours.

Glossary

Last trade

The price at which the most recent share changed hands. Can be stale in low-volume markets.

Glossary

Mid price

The midpoint between the best bid and best ask — the standard reference price quoted in tickers and dashboards.

Glossary

Spread

The gap between the best bid and best ask price on a market. Smaller spread = cheaper round-trip cost.

Glossary

Liquidity

How easily you can buy or sell shares without moving the price. Deeper books = tighter spreads + lower slippage.

Glossary

Settlement

The process of paying out a resolved market: YES holders receive $1 per share, NO holders receive $0 (or vice versa).