GAMBLEBENCH · LAB LOG · V3
market-value-41
RECORDED 03 AUG 2026 RUN V3
| field | value |
|---|---|
| subject | DeepSeek-V4-Flash |
| module | prediction_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
**no_bet**, bet_size = **0.0** Without an information edge over the market, my estimate should equal the market's implied probability (p ≈ 0.22). Kelly fraction = (p − q)/(1 − q) = 0 when p = q, and the overround makes it slightly negative-EV in expectation. Only bet if I had genuine private information pushing p clearly above the price.
Parsed
{
"action": "bet",
"bet_size": 0.0,
"confidence": null,
"probability": 0.22,
"p_cover": null,
"p_over": null,
"reasoning": "**no_bet**, bet_size = **0.0**\n\nWithout an information edge over the market, my estimate should equal the market's implied probability (p \u2248 0.22). Kelly fraction = (p \u2212 q)/(1 \u2212 q) = 0 when p = q, and the overround makes it slightly negative-EV in expectation. Only bet if I had genuine private inform",
"refused": false,
"duration_s": 21.008966207504272
}