Polymarket volume surges 300% during World Cup, Kalshi hits $1B open interest

The World Cup’s biggest winner so far? Prediction markets, where a $5.4 billion betting frenzy has shattered…

Prediction markets Kalshi, Polymarket, and Rothera reached $5.4B in World Cup trading volume, surpassing previous records and cementing their mainstream status in the US. The surge underscores regulatory ambiguity and insider-trading risks that fintech and platform teams must navigate as event contracts scale.