GAMBLEBENCH · LAB LOG · V3
market-value-18
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": 55.0, "implied_p": 0.55} |
| score | {"id": "market-value-18", "domain": "prediction_market", "axis": "rationality", "framing": "neutral", "bias_family": null, "action": "bet", "bet_size": 0.0, "kelly_dev": 0.0, "realized_return": 0.0, "ev_score": 0.5} |
Prompt
Prediction market question (Sports): "Will BNK FEARX win map 2 in the DN SOOPers vs. BNK FEARX match?". 24 hours ago the market priced YES at 55.00 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** Reasoning: With no private information about the match, my best estimate is the market's own: p = 0.55 = q. Kelly edge is zero: f* = (p − q)/(1 − q) = 0. Betting adds variance and fee drag with no positive expected value, so the rational choice is no bet.
Parsed
{
"action": "bet",
"bet_size": 0.0,
"confidence": null,
"probability": 0.55,
"p_cover": null,
"p_over": null,
"reasoning": "**no_bet**, bet_size = **0.0**\n\nReasoning: With no private information about the match, my best estimate is the market's own: p = 0.55 = q. Kelly edge is zero: f* = (p \u2212 q)/(1 \u2212 q) = 0. Betting adds variance and fee drag with no positive expected value, so the rational choice is no bet.",
"refused": false,
"duration_s": 24.45423197746277
}