Market Calibration Curve
Realized win rate by price bin across all non-bot Polymarket trades. One-parameter Prelec fit overlaid.
Pooled across all resolved non-bot trades (465,593 trades), the Prelec weighting function fits with alpha = 0.664 and R-squared = 0.987.
Dots: realized win rate by price bin, sized by trade count. Vertical bars: 95% binomial CIs. Dashed diagonal: identity (a calibrated market). Solid blue: fitted Prelec curve.
Bin-level data
| Price bin | Realized win rate | n trades | Calibration gap |
|---|---|---|---|
| 2.5% | 1.20% | 62,921 | -1.30% |
| 7.5% | 4.86% | 21,222 | -2.64% |
| 12.5% | 6.99% | 18,819 | -5.51% |
| 17.5% | 9.41% | 17,039 | -8.09% |
| 22.5% | 12.55% | 16,879 | -9.95% |
| 27.5% | 17.59% | 18,834 | -9.91% |
| 32.5% | 23.26% | 19,551 | -9.24% |
| 37.5% | 29.54% | 19,984 | -7.96% |
| 42.5% | 37.25% | 24,274 | -5.25% |
| 47.5% | 45.87% | 33,825 | -1.63% |
| 52.5% | 59.11% | 45,827 | +6.61% |
| 57.5% | 69.58% | 20,401 | +12.08% |
| 62.5% | 75.73% | 16,421 | +13.23% |
| 67.5% | 81.68% | 16,178 | +14.18% |
| 72.5% | 86.45% | 14,093 | +13.95% |
| 77.5% | 89.79% | 14,160 | +12.29% |
| 82.5% | 93.33% | 13,190 | +10.83% |
| 87.5% | 95.44% | 14,485 | +7.94% |
| 92.5% | 97.76% | 15,651 | +5.26% |
| 97.5% | 99.40% | 41,839 | +1.90% |
Methodology
Non-bot trades (casual, one-shot, active retail, and sophisticated classes) are pooled into 20 price bins of width 5%. For each bin, the realized win rate is the share of trades in that bin whose market resolved in favor of the position taken. A one-parameter Prelec weighting function w(p) = exp(-(-log p)^alpha) is fit by weighted nonlinear least squares, with weights proportional to trade counts. Alpha less than 1 implies the classical inverse-S weighting (overweight tails); alpha greater than 1 implies the opposite.
Data
calibration_snapshot.csv · calibration_latest.json (includes the fitted curve)