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Every prediction on Polymarket is structured around two core concepts: markets and events. Understanding how they relate is essential for building on the platform.

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Markets

A market is the fundamental tradable unit on Polymarket. Each market represents a single binary question with Yes/No outcomes.
Every market has:
IdentifierDescription
Condition IDUnique identifier for the market’s condition in the CTF contracts
Question IDHash of the market question used for resolution
Token IDsERC1155 token IDs used for trading on the CLOB — one for Yes, one for No
Markets can only be traded via the CLOB if enableOrderBook is true. Some markets may exist onchain but not be available for order book trading.

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Market Example

A simple market might be:
“Will Bitcoin reach $150,000 by December 2026?”
This creates two outcome tokens:
  • Yes token - Redeemable for $1 if Bitcoin reaches $150k
  • No token - Redeemable for $1 if Bitcoin doesn’t reach $100k

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Events

An event is a container that groups one or more related markets together. Events provide organizational structure and enable multi-outcome predictions.

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Single-Market Events

When an event contains just one market, it creates a simple market pair. The event and market are essentially equivalent. 
Event: Will Bitcoin reach $100,000 by December 2024?
└── Market: Will Bitcoin reach $100,000 by December 2024? (Yes/No)

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Multi-Market Events

When an event contains two or more markets, it creates a grouped market pair. This enables mutually exclusive multi-outcome predictions. 
Event: Who will win the 2024 Presidential Election?
├── Market: Donald Trump? (Yes/No)
├── Market: Joe Biden? (Yes/No)
├── Market: Kamala Harris? (Yes/No)
└── Market: Other? (Yes/No)

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Identifying Markets

Every market and event has a unique slug that appears in the Polymarket URL: 
https://polymarket.com/event/fed-decision-in-october
                              └── slug: fed-decision-in-october
You can use slugs to fetch specific markets or events from the API: 
# Fetch event by slug
curl "https://gamma-api.polymarket.com/events?slug=fed-decision-in-october"

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Sports Markets

Specifically for sports markets, outstanding limit orders are automatically cancelled once the game begins, clearing the order book at the official start time. However, game start times can shift — if a game starts earlier than scheduled, orders may not be cleared in time. Always monitor your orders closely around game start times.

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Next Steps

Prices & Orderbook

Learn how prices are determined and how the order book works.

Fetching Market Data

Start querying markets and events from the API.