'Clearly gambling': Kalshi and Polymarket accused of skirting laws on sports betting

Online prediction markets allow users to put money on the outcome of almost anything — this weekend’s NBA game between the Warriors and the Thunder, the next supreme leader of Iran, whether the government will confirm the existence of aliens.

But those markets have no state oversight and operate even in states that ban gambling.

The platforms are raising bipartisan alarms, especially related to sports gambling. As states have legalized sports betting in recent years, they’ve required...