Google Chrome to Ban Prediction Market Extensions, Impacting Polymarket and Kalshi

Google is set to block Chrome extensions linked to prediction markets, creating a new distribution challenge for platforms such as Polymarket and Kalshi even as the industry records unprecedented trading activity.

The company announced the policy update on July 1 through the Chrome for Developers blog, expanding its Regulated Goods and Services policy to explicitly prohibit extensions that facilitate predictive markets. Developers who fail to comply with the new requirements risk having their Chrome extensions removed once the policy takes effect.

Beyond prediction markets, Google also introduced stricter privacy standards for all Chrome extensions. Developers may now collect only the data necessary for a clearly disclosed, single-purpose function. They must also provide transparent explanations of their data collection practices and notify users of any future changes. In addition, Google is banning extensions designed to bypass safety protections in AI-powered services, describing the broader policy overhaul as part of its effort to strengthen user trust and privacy.

Google stated that users should have complete visibility into how their data is handled while maintaining confidence that the Chrome extension ecosystem operates responsibly.

The decision is notable because Google Finance has displayed prediction market data from Polymarket and Kalshi since November 2025. While the company continues to feature market odds on its financial platform, it is now restricting browser extensions that enable direct participation in those markets.

The move comes as prediction markets continue to expand rapidly. According to Dune Analytics, combined monthly notional trading volume reached approximately $291.38 billion as of June 22, highlighting growing investor interest despite mounting regulatory pressure.

Several jurisdictions have already imposed restrictions. Argentina ordered a nationwide block of Polymarket in March, joining more than 30 countries that have limited access to the platform. The ruling also led Google and Apple to remove Polymarket's mobile apps for users in Argentina.

In the United States, the Commodity Futures Trading Commission (CFTC) continues to defend prediction markets in court against legal challenges from several states, including Kentucky, New York, and Wisconsin.

Despite increasing scrutiny, investor interest remains strong. Kalshi is reportedly pursuing a $40 billion valuation following its $1 billion Series F funding round. Meanwhile, a Wall Street Journal analysis found that more than 70% of Polymarket accounts lost money, while just 0.1% of users captured roughly 67% of total profits. Although Chrome extensions may disappear, prediction markets remain accessible through their websites and mobile applications.