Kalshi and Polymarket ban insider trading as senators look to curb prediction markets

Top prediction market sites usher in new guardrails after senators introduced bill that could limit booming industry

Kalshi and Polymarket, the two biggest prediction market sites, rushed to institute new industry guardrails and add new surveillance tools on Monday after two key senators announced legislation that could severely curtail the industry’s prospects.

Kalshi said it would ban political candidates from trading on their own campaigns, and it would pre-emptively block anyone involved in college or professional sports from trading contracts related to the sports they play or are employed by.