Prediction Markets 101

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What Are Prediction Markets?

Prediction markets are platforms where you trade contracts on the outcomes of real-world events. Each contract resolves to either $1** (if the outcome happens) or **$0 (if it doesn’t). The current trading price reflects the market’s implied probability of that outcome. For example, if a contract “Will X happen?” trades at $0.65, the market implies a 65% probability that X will occur.

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Key Concepts

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Markets and Conditions

A market is a single tradeable question (e.g., “Will Team A win?”). Markets are identified by a condition_id, the unique identifier for the underlying question. Each market has two sides:

• Yes — you profit if the event happens
• No — you profit if the event doesn’t happen

Yes and No prices always sum to approximately $1.

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Token IDs

Each side of a market has its own token ID, the specific tradeable asset. A single condition_id maps to two token IDs (one for Yes, one for No). When placing trades or fetching prices, you’ll often work with token IDs.

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Events

An event groups related markets together. For example, “2026 Election” might be an event containing markets for each candidate.

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Orderbooks

Prediction markets use orderbooks, a list of open buy and sell orders at various prices. The orderbook determines the current best price and available liquidity. Key orderbook terms:

• Bid — highest price a buyer is willing to pay
• Ask — lowest price a seller is willing to accept
• Spread — the gap between the best bid and best ask

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Positions

When you buy shares in a market, you hold a position. Positions track:

• Which outcome you hold (Yes or No)
• How many shares
• Your average entry price

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Resolution

When the real-world event concludes, the market resolves. Winning shares pay out $1 each. Losing shares pay$0. After resolution, winning positions become redeemable and can be exchanged for your collateral (USDC.e on Polymarket, USDT on Predict.fun).

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Platforms Predexon Supports

Predexon provides a unified API across multiple prediction market platforms:

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What You Can Do with Predexon

• Read market data — prices, candlesticks, volume, open interest, orderbooks across all platforms
• Trade programmatically — place and manage orders on Polymarket and Predict.fun via the Trading API
• Analyze wallets — track positions, calculate P&L, profile trading behavior
• Find cross-platform opportunities — match equivalent markets between Polymarket and Kalshi
• Follow smart money — see where high-performing traders are active
• Stream real-time data — subscribe to trades, activity, and market lifecycle events via WebSocket