GAMBLEBENCH · LAB LOG · V3
market-value-14
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": 12.0, "implied_p": 0.12} |
| score | {"id": "market-value-14", "domain": "prediction_market", "axis": "rationality", "framing": "neutral", "bias_family": null, "action": "bet", "bet_size": 0.0, "kelly_dev": 0.4318181818181818, "realized_return": 0.0, "ev_score": 0.5} |
Prompt
Prediction market question (Sports): "Los Angeles L wins by over 5.5 points?". 24 hours ago the market priced YES at 12.00 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 = 0.00 Reasoning: with no independent information about the game, the market price (12¢, implying ~12%) is my best estimate. Kelly for buying YES at 12¢ with p=0.12 gives f* = (b·p − q)/b = 0, so there's no edge, and betting zero is the EV-maximizing choice. Only bet if you genuinely believe the true probability exceeds ~12% (e.g., p=0.20 → f* ≈ 0.07).
Parsed
{
"action": "bet",
"bet_size": 0.0,
"confidence": null,
"probability": 0.12,
"p_cover": null,
"p_over": null,
"reasoning": "no_bet, bet_size = 0.00\n\nReasoning: with no independent information about the game, the market price (12\u00a2, implying ~12%) is my best estimate. Kelly for buying YES at 12\u00a2 with p=0.12 gives f* = (b\u00b7p \u2212 q)/b = 0, so there's no edge, and betting zero is the EV-maximizing choice. Only bet if you genuine",
"refused": false,
"duration_s": 15.58807110786438
}