U.S. prediction markets are accelerating toward professionalization, and the advantage of "skilled traders" may be compressed.

A study of prediction market platform Polymarket shows that among the $13.76 billion in trades they analyzed, about 3% of accounts were identified as "skilled traders" with a persistent trading edge, and these accounts captured about 27% of total profits. These traders mainly profit by digesting public news more quickly, arbitraging inconsistent pricing between related contracts, and exploiting the behavioral biases of other participants. But as more and more professional participants chase the same opportunities, these advantages will be further compressed.