GAMBLEBENCH · LAB LOG · V3
market-value-40
RECORDED 03 AUG 2026 RUN V3
| field | value |
|---|---|
| subject | DeepSeek-V4-Flash |
| module | prediction_market · rationality |
| ground truth | {"type": "market_value", "outcome": 1, "price_q0": 45.0, "implied_p": 0.45} |
| score | {"id": "market-value-40", "domain": "prediction_market", "axis": "rationality", "framing": "neutral", "bias_family": null, "action": "bet", "bet_size": 0.0, "kelly_dev": 0.09090909090909088, "realized_return": 0.0, "ev_score": 0.5} |
Prompt
Prediction market question (Sports): "Philadelphia at Winnipeg Winner?". 24 hours ago the market priced YES at 45.00 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 = 0.00) Reasoning: I have no edge over the market here. My honest estimate for Philadelphia winning on the road in Winnipeg is ~35–40%, well below the 45¢ ask, so buying YES is negative-EV (I'd only bet YES if my estimate exceeded the price). With no positive edge, the Kelly-optimal position is zero. I'd only take the other side (NO) if selling short were allowed.
Parsed
{
"action": "bet",
"bet_size": 0.0,
"confidence": null,
"probability": 0.4,
"p_cover": null,
"p_over": null,
"reasoning": "**Decision: no_bet** (bet_size = 0.00)\n\nReasoning: I have no edge over the market here. My honest estimate for Philadelphia winning on the road in Winnipeg is ~35\u201340%, well below the 45\u00a2 ask, so buying YES is negative-EV (I'd only bet YES if my estimate exceeded the price). With no positive edge, th",
"refused": false,
"duration_s": 18.898559093475342
}