Event-driven#227tier 2experimentalNew

polymarket resolution drift

cadence: Event-drivendata: mediumlong onlyshort only
paper
2008
Source
Extends: Berg, J.E., Nelson, F.D., Rietz, T.A. (2008). "Prediction market accuracy in the long run." International Journal of Forecasting 24(2). Pre-resolution mean-revert is novel (alphactor 2026-05-20).
Read the paper →

What it checks

In the last 5 days before a polymarket resolves, the YES price often overshoots its all-time fair value. We mean-revert: short when overshot up, long when overshot down.

Mechanism

In the last ~5 trading days before a polymarket resolves, the YES price becomes noisy — microstructure flows, low liquidity, and asymmetric information distort the price. Extreme reads in the terminal window MEAN-REVERT to the lifetime volume-weighted fair value, NOT to the eventual outcome. The equity then follows the prediction-market direction.

No production champion data for this family yet. Stats appear once the discovery pipeline promotes at least one strategy with this family tag, or once a multi-family blend that includes it earns a champion slot.

Signal rule

Within 5d of resolution_date, if |z(yes − fair_value)/σ_yes| ≥ threshold → take position in -sign(z) direction. Hold 1/3/5d. T+1 lag.

Data dependencies

  • daily_prices

    Adjusted-close OHLCV for every US-listed ticker; primary price feed.

  • polymarket_markets

    Worker data table — see services/worker schema.

  • polymarket_prices_daily

    Worker data table — see services/worker schema.

Expected edge

Paper alpha
untested — moonshot
Paper window
T-5 to T+5 around resolution

Untested — moonshot. Target 50-150 bps per qualifying terminal-window fire; ~10-30 fires per linked ticker per year.

Example tickers where this is likely to fire

Illustrative only — the signal fires based on the live data, not a fixed list.

Related families

Explore polymarket resolution drift on alphactor.ai

See which tickers this family is currently firing on, with live signals and rankings.

For informational and educational purposes only. Not financial advice. Learn more