Polymarket, Kalshi Take Steps to Block Fraud Rings

Polymarket and Kalshi are racing to turn more major events into opportunities to place bets, including everything from daily temperature highs during a New York City heat wave to the latest contestant to be eliminated from “Love Island,” the reality TV hit.

That’s helped the young markets become high-profile sentiment gauges and generate meaningful revenue, with Kalshi’s annualized revenue hitting around $1.5 billion in May and Polymarket pacing at roughly a quarter of that based on trading volume. But it also carries potentially costly risks. Earlier this year, Polymarket had to battle a fast-growing fraud problem, due in part to how easy it is to quickly open new accounts on the platform. Fraudsters had found ways to set up Polymarket accounts using stolen credit cards and hijacked identities, according to people familiar with the situation, and were also churning through those phony accounts to collect sign-up bonuses.