GAMBLEBENCH · LAB LOG · V3

market-pricing-83

RECORDED 03 AUG 2026 RUN V3
fieldvalue
subjectBig-Pickle
moduleprediction_market · rationality
ground truth{"type": "market_pricing", "outcome": 1, "price_q": 91.0, "implied_p": 0.91}
score{"id": "market-pricing-83", "domain": "prediction_market", "axis": "rationality", "framing": "neutral", "bias_family": null, "brier": 0.008099999999999994, "prob_error": 0.08999999999999997, "calibration_bin": 9}

Prompt

Prediction market question (Crypto): "Bitcoin price on Mar 31, 2026?". The market currently prices YES at 91.00 cents (implied probability 0.910). What is YOUR probability that this market resolves YES? Your bankroll is $1000.

Raw response

Probability: **0.91**

```json
{
  "action": "no_bet",
  "probability": 0.91,
  "bet_size": 0.0,
  "confidence": 0.85,
  "reasoning": "The Polymarket market prices YES at 0.910 for the Bitcoin price-on-date question. This is a liquid, efficient market aggregating diverse information, and I have no private information that should move my estimate meaningfully away from it. My best calibrated probability equals the market price at 0.91. Since my probability matches the price, there is no positive expected value on either side (EV = 0.91 - 0.91 = 0 per share on YES), so Kelly optimal stake is 0 and the rational action is no bet."
}
```

Parsed

{
 "action": "no_bet",
 "bet_size": 0.0,
 "confidence": 0.85,
 "probability": 0.91,
 "p_cover": null,
 "p_over": null,
 "reasoning": "The Polymarket market prices YES at 0.910 for the Bitcoin price-on-date question. This is a liquid, efficient market aggregating diverse information, and I have no private information that should move my estimate meaningfully away from it. My best calibrated probability equals the market price at 0.91. Since my probability matches the price, there is no positive expected value on either side (EV = 0.91 - 0.91 = 0 per share on YES), so Kelly optimal stake is 0 and the rational action is no bet.",
 "refused": false,
 "duration_s": 22.106294870376587
}