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Updated September 25, 2026 · numbers refresh automatically from this site's data
Yes. A 90% price means the outcome should fail about one time in ten. In our sample of 1,918 resolved Polymarket markets that closed between September 25, 2025 and September 21, 2026, outcomes priced 90% or more a week before the close happened 95% of the time: 3 of 62 lost. Long shots priced 20% or less came through 82 times out of 1,413 (5.8%, against an average price of 3.2%).
If prices are well calibrated, outcomes priced near 90% should happen about 90% of the time, and those priced near 10% about 10% of the time. Here is the full sample, priced seven days before each market closed:
| Price a week before close | Markets | Average price | Happened |
|---|---|---|---|
| 0–10% | 1,243 | 1.7% | 3.9% |
| 10–20% | 165 | 14.2% | 19.4% |
| 20–30% | 116 | 24.5% | 25.9% |
| 30–40% | 78 | 34.8% | 42.3% |
| 40–50% | 70 | 45.1% | 45.7% |
| 50–60% | 71 | 54.3% | 60.6% |
| 60–70% | 49 | 65.0% | 73.5% |
| 70–80% | 41 | 74.7% | 63.4% |
| 80–90% | 23 | 85.1% | 87.0% |
| 90–100% | 62 | 96.1% | 95.2% |
Method, caveats and the data file: How accurate is Polymarket? Small bands move a lot by chance.
Outcomes that were priced at 20% or less a week before the close and still happened:
| Market | Outcome that won | Price a week out | Closed |
|---|---|---|---|
| What price will Bitcoin hit in August? | ↑ 80,000 | 0.5% | August 24, 2026 |
| What price will Bitcoin hit in August? | ↑ 77,500 | 1.1% | August 21, 2026 |
| What price will Bitcoin hit in August? | ↑ 75,000 | 2.6% | August 21, 2026 |
| What price will Bitcoin hit in August? | ↑ 72,500 | 7.5% | August 20, 2026 |
| What price will Bitcoin hit in August? | ↑ 70,000 | 15.0% | August 19, 2026 |
| NBA: LeBron James Next Team | Philadelphia 76ers | 8.9% | July 27, 2026 |
| 2026 Women's Wimbledon Winner | Linda Nosková | 4.5% | July 11, 2026 |
| Argentina vs. Cabo Verde | Draw (Argentina vs. Cabo Verde) | 11.5% | July 4, 2026 |
Full list: biggest Polymarket upsets.
Short, mechanical markets behave differently: in 1,008 daily Bitcoin and Ethereum price strikes, the side priced above 50% a day ahead won 95% of the time, and all 527 strikes priced 90% or more happened (crypto accuracy study).
Size positions so that a favorite losing does not hurt: the Kelly calculator gives a stake for your edge and the risk of ruin calculator shows how often a stake size halves a bankroll. The calibration and favorite–longshot bias entries explain the terms.
Yes. A 90% price means the outcome should fail about one time in ten. In our sample of 1,918 resolved Polymarket markets that closed between September 25, 2025 and September 21, 2026, outcomes priced 90% or more a week before the close happened 95% of the time: 3 of 62 lost. Long shots priced 20% or less came through 82 times out of 1,413 (5.8%, against an average price of 3.2%).
Outcomes priced at 50% or more a week before the close happened 75% of the time in our sample of 1,918 resolved markets.
Yes: 82 of 1,413 outcomes priced 20% or less a week out happened in our sample.
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