Prediction Markets Broke My Brain About Probability

An analysis of 47,342 prediction market traders graded on ~40 metrics reveals that most traders lose money — not because of insufficient capital, but poor judgment. The median trader's P&L is nearly zero, while F-grade traders with $2.2M median volume still lose. Top performers (S-grade) trade across thousands of markets with small, diversified positions rather than concentrated high-conviction bets. The key insight: confidence is almost completely uncorrelated with accuracy, and the best traders already know this.