How to Read Polymarket Odds: Price = Probability (October 2026)
On Polymarket, price is probability: a YES share trading at 65¢ means the market sees roughly a 65% chance of the event happening, and that share pays exactly $1 if it resolves YES (or $0 if not). No decimal, fractional, or American conversion is needed to understand the headline number — the cents on screen are the implied odds.
How do I convert a Polymarket price to a probability?
Divide the price by $1.00 — that is the whole conversion:
| Share price | Implied probability | Payout if YES |
|---|---|---|
| $0.05 | 5% | $1.00 (20x return) |
| $0.50 | 50% | $1.00 (2x return) |
| $0.73 | 73% | $1.00 (1.37x return) |
| $0.99 | 99% | $1.00 (1.01x return) |
The NO side is the mirror: if YES costs 65¢, NO costs 35¢ (a 35% implied chance), modulo the spread. Both sides always sum near $1.00 across a binary market.
What other odds formats does Polymarket support?
The interface can display eight formats, all derived from the same price:
| Format | 65¢ YES displays as |
|---|---|
| Price (default) | $0.65 |
| Percent | 65% |
| American | −186 |
| Decimal | 1.54 |
| Fractional | 0.54/1 |
| Indonesian | −1.86 |
| Hong Kong | 0.54 |
| Malaysian | 0.54 |
American odds for favorites are negative (−186 means stake 186 to win 100); for longshots positive (+258 for a 28¢ share).
How do multi-outcome events work?
In a race with 20 candidates, each outcome is its own YES/NO market. Implied probabilities across all candidates should sum near 100%, but two distortions are normal: the bid/ask spread (each market quotes a range, not a point) and lazy longshot pricing on candidates with no real chance. When the sum is 103%, that 3% is spread cost — the house edge you pay to enter and exit, not a market opinion.
Why does price drift from true probability?
Three structural reasons:
- Spread and liquidity — thin books quote wide, and the last trade may be stale rather than informative
- Fee asymmetry — taker fees (up to $1.75 per 100 shares in crypto) nudge quoted prices away from fair value
- Capital limits — if nobody can afford to correct a mispricing, the wrong price can persist; Polymarket whales are not infinite
The practical skill: treat the price as the market’s opening argument, then check the order book depth, recent trade sizes, and resolution rules before treating it as truth.
How do I read the order book price properly?
The last trade is not the price. The midpoint between best bid and best ask is a better live estimate, and the book depth tells you how much size the quote can actually absorb. A 65¢ midpoint with $200 of depth is a different fact than 65¢ with $200,000 of depth.
FAQ
Q: What does 73¢ on Polymarket mean? A: The market prices roughly a 73% chance of that outcome. If it resolves YES, each share pays $1.00 — a 37% return on the 73¢ entry.
Q: How do I convert Polymarket odds to American odds? A: For prices above 50¢: American = −100 × p/(1−p) where p is the probability (65¢ → −186). Below 50¢: +100 × (1−p)/p (35¢ → +186).
Q: Do YES and NO always sum to $1? A: The implied probabilities sum to slightly over 100% in practice because of the bid/ask spread — that excess is the round-trip cost, similar to a bookmaker’s overround.
Q: Which odds format should I use? A: Price or percent — they are the most direct. Decimal is useful for quick payout math: payout multiple = 1/price (a 40¢ share is 2.5x if it wins).
Q: Is a 99¢ share a guaranteed win? A: No. It is a 99% market-implied chance — roughly 1-in-100 of these resolves NO. Residual risk is the price of the 1¢ upside.
Sources
Disclaimer
Not financial advice. Educational purposes only. Updated October 2026.
