GAMBLEBENCH · LAB LOG · V3
market-value-49
RECORDED 03 AUG 2026 RUN V3
| field | value |
|---|---|
| subject | Big-Pickle |
| module | prediction_market · rationality |
| ground truth | {"type": "market_value", "outcome": 0, "price_q0": 29.0, "implied_p": 0.29} |
| score | {"id": "market-value-49", "domain": "prediction_market", "axis": "rationality", "framing": "neutral", "bias_family": null, "action": "bet", "bet_size": 0.0, "kelly_dev": 0.295774647887324, "realized_return": 0.0, "ev_score": 0.5} |
Prompt
Prediction market question (Sports): "Carolina wins by over 1.5 goals?". 24 hours ago the market priced YES at 29.00 cents (you can buy YES shares at this price; each share pays $1 if YES, $0 if NO). Your own probability estimate is up to you. Your bankroll is $1000. Decide: bet or no_bet, and bet_size as a fraction of bankroll.
Raw response
**Bet: no_bet, bet_size: 0** With no private information beyond the market price, my best estimate of P(Carolina wins by 2+) ≈ 0.29, which is exactly the ask price — zero expected edge. Buying YES at 29¢ for a fair 29% event is a wash before fees and loses to the spread. I'd only bet if I had genuine information this matchup that the market lacks.
Parsed
{
"action": "bet",
"bet_size": 0.0,
"confidence": null,
"probability": 0.29,
"p_cover": null,
"p_over": null,
"reasoning": "**Bet: no_bet, bet_size: 0**\n\nWith no private information beyond the market price, my best estimate of P(Carolina wins by 2+) \u2248 0.29, which is exactly the ask price \u2014 zero expected edge. Buying YES at 29\u00a2 for a fair 29% event is a wash before fees and loses to the spread. I'd only bet if I had genui",
"refused": false,
"duration_s": 10.540781021118164
}