Two leading prediction-market platforms have rolled out tighter guardrails on Monday to curb insider trading and suspected market manipulation in event-based contracts, as lawmakers in Washington step up scrutiny of a sector that blends finance, law and politics.

Kalshi and Polymarket argued that their updates are designed to prevent the exploitation of confidential information and to reduce the risk that markets skew the outcomes of real-world events. The moves come amid a broader policy push in the United States to regulate or restrict prediction markets that resemble gambling or sports betting.

Key takeaways

• Kalshi and Polymarket introduced new guardrails to combat insider trading and manipulation in event contracts.
• Kalshi will preemptively bar political candidates from trading on their campaigns and exclude individuals connected to college and professional sports from relevant markets.
• Polymarket expanded prohibitions to forbid trades based on stolen confidential information or those who can influence market outcomes.
• A bipartisan bill, the Prediction Markets Are Gambling Act, would bar CFTC-registered platforms from listing event contracts that resemble sports bets or casino-style games.
• The policy debate highlights tensions over jurisdiction, licensing and the boundaries between financial markets and entertainment-oriented betting.

Guardrails tighten as Congresseye rules intensify

Kalshi said it would preemptively ban political candidates from trading on their own campaigns, along with individuals known to be involved in college and professional sports—such as athletes, staff, and referees. The exchange described the move as part of a long-running effort to align with evolving regulatory guidance and proposed legislation addressing insider trading and market manipulation in prediction markets.

In a separate but related move, Polymarket unveiled broader prohibitions intended to close loopholes that could enable insiders to benefit from confidential information or influence the outcome of a contract. The company said its updated rules aim to make the market more resistant to manipulation and to protect the integrity of events traded on its platform.

The changes come on the heels of intense public debate about whether some well-timed bets on political or geopolitical events reflect legitimate market activity or exploit privileged information. In recent coverage, observers noted bets placed around high-profile events such as U.S. and Israeli actions in Iran and a U.S.-led operation related to Venezuela’s Nicolás Maduro, with some traders appearing to use multiple accounts to mask activity. The Guardian reported that the Iran-strike bets were made by users who could be perceived as having inside information, underscoring the ongoing concerns about insider knowledge shaping market outcomes.

Kalshi described its policy evolution as a proactive response to the regulatory environment and to proposed congressional action. The company, which is a member of the Coalition for Prediction Markets, argued that these guardrails are part of preparing for potential legal guidance and legislative developments that address insider trading and market manipulation in prediction markets.

Policy spotlight: bipartisan efforts and legal tensions

On Monday, Democratic Senator Adam Schiff and Republican Senator John Curtis introduced a bipartisan bill, the Prediction Markets Are Gambling Act, that would bar Commodity Futures Trading Commission-registered entities from listing event contracts that resemble sports betting or casino-style games. In their view, sports prediction contracts are effectively sports bets—an assertion Schiff has repeated to emphasize the public-law implications of these instruments when they resemble gambling more than information-driven markets.

The proposed legislation would withdraw a key allowance for platforms like Kalshi and Polymarket by limiting what contracts they may offer in the United States. Schiff’s office framed the issue as one of regulatory clarity and consumer protection, while Curtis stressed maintaining state authority over broader gaming and betting activities.

Kalshi’s chief executive, Tarek Mansour, reacted to the bill by framing the move within a broader “casino lobby” effort. He argued that the legislation is not about protecting consumers but about preserving entrenched monopolies, a line he shared publicly on social media. His comments underscore how industry actors view the political dynamic surrounding prediction markets and their place in the U.S. financial-regulatory landscape.

Legal tension has already surrounded prediction-market operators in several states, which have asserted that sports-event contracts constitute gambling that requires a state license. Platforms such as Kalshi, Polymarket andCoinbase have contended that their offerings are not illegal betting and, regardless, fall under the exclusive jurisdiction of the Commodity Futures Trading Commission rather than state authorities.

The policy debate is not theoretical for traders and developers who rely on prediction markets for hedging and information discovery. As reported by Cointelegraph, the U.S. Senate has been weighing bills aimed at curtailing or redefining the reach of these markets, alongside state-level actions that challenge the legality of specific contracts. The ongoing legal and regulatory discourse creates an environment of uncertainty, even as platforms push for clearer rules that would allow compliant operation in the United States.

For context, Cointelegraph’s reporting has highlighted instances where traders leveraged event-driven markets to capitalize on geopolitical developments, reinforcing concerns about information asymmetry and the potential for manipulation. The new guardrails by Kalshi and Polymarket are thus part of a broader effort to reconcile the commercial appeal of prediction markets with legitimate safeguards against abuse.

What to watch next in the evolving landscape

As lawmakers advance their proposals and courts consider disputes over jurisdiction and licensing, the trajectory of prediction markets in the United States remains uncertain. If the proposed act passes, CFTC-approved platforms could face tighter restrictions or even a narrowed set of permissible contracts, potentially dampening growth but improving trust and regulatory compliance.

For users, traders and builders, the key questions are how the guardrails translate into practical trading limits, whether state or federal rules will ultimately prevail, and how enforcement will unfold in a landscape that often intersects with political sentiment and sports governance.

The next chapter will likely hinge on legislative momentum in Congress and any legal clarifications from federal or state authorities. Watch for updates on whether the bipartisan bill gains traction, how the industry responds with further rule adjustments, and whether there are new developments in the ongoing legal actions against these platforms. The balance between innovation and integrity in prediction markets remains delicate, and investors should monitor both regulatory signals and platform-level safeguards as the market evolves.

Sources: Kalshi newsroom announcements on guardrails; Polymarket rule updates; U.S. Senate press releases announcing the proposed act; coverage of insider-trading concerns around event contracts; The Guardian reporting on Iran-strike bets; ongoing state-level legal actions against prediction-market operators.