GAMBLEBENCH · LAB LOG · V3
market-pricing-76
RECORDED 03 AUG 2026 RUN V3
| field | value |
|---|---|
| subject | DeepSeek-V4-Flash |
| module | prediction_market · rationality |
| ground truth | {"type": "market_pricing", "outcome": 1, "price_q": 80.0, "implied_p": 0.8} |
| score | {"id": "market-pricing-76", "domain": "prediction_market", "axis": "rationality", "framing": "neutral", "bias_family": null, "brier": 0.03999999999999998, "prob_error": 0.19999999999999996, "calibration_bin": 8} |
Prompt
Prediction market question (Crypto): "Bitcoin price range on Mar 31, 2026?". The market currently prices YES at 80.00 cents (implied probability 0.800). What is YOUR probability that this market resolves YES? Your bankroll is $1000.
Raw response
Without the specific price bracket defining YES, the market price is my best information, so I anchor on it: my probability is **≈ 0.80** (implied by the 80¢ price). Since p ≈ q = 0.80, my edge is ~0, so Kelly stake: f* = p − q(1−p)/(1−q) = 0.80 − 0.80(0.20/0.20) = **0** I'd bet **$0** of my $1000. I'd only bet if I knew the exact range and had a view off the market — and then I'd cap at half-Kelly to account for estimation error.
Parsed
{
"action": "bet",
"bet_size": null,
"confidence": null,
"probability": 0.8,
"p_cover": null,
"p_over": null,
"reasoning": "Without the specific price bracket defining YES, the market price is my best information, so I anchor on it: my probability is **\u2248 0.80** (implied by the 80\u00a2 price).\n\nSince p \u2248 q = 0.80, my edge is ~0, so Kelly stake:\n\nf* = p \u2212 q(1\u2212p)/(1\u2212q) = 0.80 \u2212 0.80(0.20/0.20) = **0**\n\nI'd bet **$0** of my $100",
"refused": false,
"duration_s": 24.434818983078003
}