Market mechanics
Prediction Market Spread Explained
Learn how bid-ask spreads affect displayed probabilities, execution quality and the usefulness of a prediction-market price.
Educational note: This article explains market structure and probability reading. It is not financial, legal or trading advice.
What a spread is
The spread is the gap between the best available buy and sell prices. A market may display a midpoint, last price or chart value, but the executable price can be different.
Why it matters
- Wide spreads make small probability differences less meaningful.
- Thin order books can make a displayed price hard to use.
- Comparisons across platforms should use executable prices, not only headlines.
Research approach
When using a price for research, note whether it is a last trade, midpoint, best bid or best ask. A 55% headline with a wide spread may be much less precise than it appears.
Reader checklist: compare the market wording, price, liquidity and resolution source before treating any probability as meaningful.
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