Polymarket Loses Prediction-Market Lead After Delays, Blowback

Polymarket, the long-time leader in prediction market trading volume, has fallen behind its chief rival as it faces a growing list of operational stumbles in its attempt to reach a crucial audience: US customers.

A string of delays, in addition to the startup's disruptive approach to an already disruptive industry, has drawn blowback from customers and lawmakers, and at times even tested the patience of its biggest investor, , according to people familiar with the situation.

The setbacks are shaping a battle for the soul of a booming industry that is trying to change the nature ...