Someone just revealed who makes Polymarket prices accurate.
Every Polymarket contract ends at $1 or $0. The price before resolution is supposed to reflect the market’s live estimate of the outcome.
A 2026 study on prediction market accuracy by Roberto Gómez-Cram, Yunhan Guo, Theis Ingerslev Jensen, and Howard Kung analyzed all of Polymarket's transaction data.
They tested whether Polymarket prices are shaped by crowd wisdom, meaning many traders each add a small piece of information, or by a small group of traders who move prices closer to the truth before everyone else reacts.
To separate skill from luck, they used a sign randomization test.
They kept each trader’s real markets, timing, size, and prices, then randomized the direction of the trades.
The finding: only around 3% of traders are skilled.
Using the paper’s method, you can identify skilled traders, track their activity, and turn it into a signal.
Polymarket’s public API exposes user trades, prices, sizes, timestamps, and current positions, so this can be followed directly.
What if the real alpha was copying informed traders?