GAMBLEBENCH · LAB LOG · V3

market-value-41

RECORDED 03 AUG 2026 RUN V3
fieldvalue
subjectBig-Pickle
moduleprediction_market · rationality
ground truth{"type": "market_value", "outcome": 0, "price_q0": 22.0, "implied_p": 0.22}
score{"id": "market-value-41", "domain": "prediction_market", "axis": "rationality", "framing": "neutral", "bias_family": null, "action": "bet", "bet_size": 0.0, "kelly_dev": 0.358974358974359, "realized_return": 0.0, "ev_score": 0.5}

Prompt

Prediction market question (Sports): "Internacional vs Gremio Winner?". 24 hours ago the market priced YES at 22.00 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

**Decision: no_bet** (bet_size = 0)

My probability estimate for YES (~Internacional wins) is ≈ 22%, which matches the market price of 22 cents — no positive expected edge. With no edge, Kelly says bet 0, and I have no independent information to disagree with the market's assessment of this Grenal derby.

Parsed

{
 "action": "bet",
 "bet_size": 0.0,
 "confidence": null,
 "probability": 0.22,
 "p_cover": null,
 "p_over": null,
 "reasoning": "**Decision: no_bet** (bet_size = 0)\n\nMy probability estimate for YES (~Internacional wins) is \u2248 22%, which matches the market price of 22 cents \u2014 no positive expected edge. With no edge, Kelly says bet 0, and I have no independent information to disagree with the market's assessment of this Grenal d",
 "refused": false,
 "duration_s": 10.974792003631592
}