Prediction markets are becoming more professionalized, but also harder to beat

Prediction-market platforms' courtship of Wall Street stands to bring in deeper professional liquidity and intensify competition, but will also mean it's harder for many traders to make money. Roughly 27% of dollar profits were captured by just 3% of accounts that are "persistently skilled," repeatedly moving market prices towards outcomes that eventually occurred, according to an academic working paper analyzing $13.76 billion of Polymarket trades. Skilled accounts earned consistent profits by reacting more quickly to publicly available news, arbitraging inconsistent pricing across related contracts and trading against behavioral errors.