Markets: Prediction Market Structure on Polymarket

Learn how Polymarket prediction markets are structured in Orbscan — identifiers, outcome tokens, categories, and how resolved markets work.

A Polymarket market is a question about a future event — for example, “Will France win on 2026-06-30?” — that resolves to one of a fixed set of outcomes on a specific date. Most markets are binary, resolving to either Yes or No, though multi-outcome markets exist for events with several candidates or options. Traders buy shares in the outcome they believe will occur, and each winning share pays out exactly $1 (100¢) at resolution. Orbscan indexes every active and resolved Polymarket market and exposes their full detail through the activity and transaction endpoints.

Market Identifiers

Every market in Orbscan carries multiple identifiers, each serving a different purpose:

Identifier	Type	Description
marketId	string	A numeric string uniquely identifying the market (e.g., "2707644"). Use this to filter activity responses via the marketIds query parameter.
marketSlug	string	A URL-friendly, human-readable string (e.g., "fifwc-fra-swe-2026-06-30-fra"). Stable across API versions and useful for display.
conditionId	string	A 0x-prefixed on-chain hash that identifies the market’s condition contract on Polygon (e.g., "0x378f7b5c..."). Use this to verify market data against the blockchain directly.
eventSlug	string	Groups related markets under a shared parent event (e.g., "fifwc-fra-swe-2026-06-30" groups all match-outcome markets for a single fixture).

When you retrieve trader activity from Orbscan, every activity item includes marketId, marketSlug, eventSlug, conditionId, and marketTitle — giving you everything you need to identify and cross-reference the market without a separate lookup.

Outcome Tokens

Each binary market has two outcome tokens — one for Yes and one for No. These are ERC-1155 tokens on Polygon that represent shares in a particular outcome.

Field	Description
tokenId	The numeric string ID of the specific outcome token traded (e.g., the Yes token or the No token).
positionSide	"Yes" or "No" — which outcome the token and trade correspond to.
outcomeIndex	0 for Yes, 1 for No. This is the index of the outcome within the market’s outcome array.

When a trader buys Yes shares, the tokenId refers to the Yes outcome token for that market. When the market resolves Yes, only holders of the Yes token can redeem.

Market Categories

Orbscan organizes markets into topic categories so you can quickly surface relevant questions:

Politics

Elections, legislation, geopolitics, and government policy.

Sports

Match outcomes, championships, player awards, and tournament brackets.

Crypto

Prices, protocol upgrades, token launches, and on-chain metrics.

Finance

Stock prices, ETF approvals, earnings results, and market indices.

Tech

Product launches, AI milestones, regulatory decisions, and company events.

Economics

GDP, inflation, unemployment, and macroeconomic indicators.

Culture

Entertainment, awards, viral events, and social trends.

Weather

Temperature records, storm events, and climate benchmarks.

Mentions

Whether a specific topic, person, or phrase will be mentioned in a defined context.

Market Logo

Every market in Orbscan includes a logo field (also returned as marketLogo on transaction action records) — a URL pointing to the market’s cover image hosted on Polymarket’s CDN. Use this field to render market thumbnails in your UI without managing image assets yourself.

"logo": "https://polymarket-upload.s3.us-east-2.amazonaws.com/soccer-ball.png"

How Markets Appear in Orbscan Responses

You don’t query markets as standalone resources in the Orbscan API — market data is embedded directly on activity and transaction records. Every item in an activity response carries the full market context you need:

{
  "marketId": "2707644",
  "marketSlug": "fifwc-fra-swe-2026-06-30-fra",
  "marketTitle": "Will France win on 2026-06-30?",
  "eventSlug": "fifwc-fra-swe-2026-06-30",
  "conditionId": "0x378f7b5c668014d9f6c42c305ec83902f3c8f6c770b336363aed0076ce6ce1c9",
  "positionSide": "Yes",
  "outcomeIndex": 0,
  "tokenId": "91355094557016369228768123360298492968992168419338047915199416797057852525950",
  "logo": "https://polymarket-upload.s3.us-east-2.amazonaws.com/soccer-ball.png"
}

This design means a single activity query gives you both the trade details and the market context in one response — no additional round-trip required.

Resolved Markets and Redeems

When a market resolves, Polymarket declares one outcome as correct. Traders who hold shares of the winning outcome can then submit a Redeem transaction to collect their payout.

In Orbscan activity data, a resolved market redemption looks like this:

• action is "Redeem"
• price is 100.0 — the winning share redeems at exactly 100¢ ($1)
• positionSide is the winning outcome (e.g., "Yes")
• transferNetAmount is negative — USDC flows out of the contract into the trader’s wallet (Orbscan signs this from the market’s perspective)
• liquidityRole is null — no order book matching occurs at redemption

Shares of the losing outcome expire worthless at resolution. There is no Redeem record for the losing side — those tokens simply become unexercisable.

Resolved market history remains fully queryable through Orbscan. Even after a market closes, you can retrieve every trade that occurred in it by filtering activity with the market’s marketId.