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Overview
Core Concepts
    Events, contracts, and outcomesCombo contracts
Market Data
    OverviewFetching Markets
    Ticker formats
      OverviewCryptoSportsSports Market TaxonomyCommoditiesWeather
Trading
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    Full REST reference
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      Events
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      Utility
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Ticker formats

Ticker Overview

Gemini prediction markets use structured ticker symbols to uniquely identify events and contracts. All tickers use the GEMI- prefix.

Event and Contract Hierarchy

All prediction markets follow a two-level structure:

  • Event - The outcome being predicted (e.g., a game, a price threshold, an election)
  • Contracts - The tradeable positions within that event (e.g., Team A wins, Team B wins)

Contract tickers are always mapped to their parent event. When querying the API, you can retrieve all contracts for an event or trade individual contracts directly.

Automated Market Tickers

Markets with programmatic resolution use structured ticker formats that encode event details directly:

Market TypeFormat
CommoditiesGEMI-{Commodity}{Expiry}-{Contract}
CryptoGEMI-{Asset}{Expiry}-{Contract}
SportsGEMI-{League}-{DateTime}-{Away}-{Home}-{Type}-{Contract}
WeatherGEMI-{EventType}-{Location}-{Expiry}-{Contract}

These tickers are deterministic - you can parse them to extract event metadata like expiry time, teams, or underlying asset.

Other Markets

Markets without automated resolution (e.g., political events, custom predictions) use unique identifiers that don't follow a structured format. The event → contract hierarchy still applies - contracts are grouped under their parent event and can be queried via the API.

Fetching MarketsCrypto
On this page
  • Event and Contract Hierarchy
  • Automated Market Tickers
  • Other Markets