[polymarket][news] Iran-war geopolitical event study methodology — INCONCLUSIVE

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polymarketnewsevent-studyinconclusive   Priority: 3   Source: polymarket-d3   Created: 2026-05-20   Updated: 2026-05-20

Hypothesis

Polymarket prices on Iran-linked outcome markets exhibit statistically distinguishable cumulative abnormal returns (CAR) in the ±30-hour window around publicly reported geopolitical news shocks, versus a pre-event drift baseline.

Data used

Method

For each event $e$ at time $t_0$: $$\text{baseline_drift} = \frac{1}{T_{pre}}\sum_{t=t_0-30}^{t_0-1} r_t$$ $$\text{CAR}{30h} = \frac{p{t_0+30} - p_{t_0-1}}{p_{t_0-1}} - 30 \cdot \text{baseline_drift}$$ $$\text{signed_CAR} = \text{direction}(e) \times \text{CAR}_{30h}$$ where $\text{direction}(e) \in {+1,-1}$ encodes the theoretically expected sign from news classification.

Sign test: $H_0$: P(signed CAR > 0) = 0.5. t-test on 30h signed CAR mean.

Result

Event Market p_pre p_t0 p_post30h CAR% signed_CAR% t-stat p-val
E1 Ceasefire extension btc_150k 0.0145 0.0145 0.0240 +34.1 +34.1 1.03 0.30
E2 Ceasefire extension iran_regime_fall 0.0455 0.0450 0.0330 -72.4 +72.4 -1.83 0.07
E3 Axios one-page memo iran_regime_fall 0.0245 0.0235 0.0215 -6.4 +6.4 -0.29 0.77
E4 Trump bomb threat iran_regime_fall 0.0205 0.0205 0.0215 +22.1 +22.1 1.39 0.17
E5 Trump-Xi summit trump_say_iran_xi 0.6300 0.5400 0.7455 +38.1 +38.1 1.54 0.12
E6 Flights resume Tehran iran_airspace 0.1800 0.1150 0.1550 -11.2 +11.2 -0.36 0.72

Aggregate (30h): Mean signed CAR = +30.7%, SD = 23.9%, hit rate = 6/6, sign test p = 0.0156 6h window: Mean signed = +17.6%, SD = 43.2%, hit rate = 4/6, t-stat = 1.00, p = 0.36

Verdict: INCONCLUSIVE — n=6 < 30 threshold; individual events not statistically significant. Sign test is technically significant (p=0.016) but with only 6 observations this is fragile.

Reproduction

source ~/.pmvenv/bin/activate
python3 /mnt/projects/tnt_85c10df4451042ca/prj_c7cb91b70b2f42ac/d3_event_study.py
# Data snapshot: /tmp/pm_data/prices_history.json
# Results: /tmp/pm_data/event_study_results.csv

Failure mode / next step

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