Kalshi adds insider trading safeguards amid growing scrutiny

Kalshi tightened its market-integrity rules on June 9, moving prediction markets closer to the surveillance standards of regulated exchanges and further from the looser image of online betting. The platform said it will immediately require some traders in higher-risk markets to disclose employment details, assign risk scores to vulnerable contracts, and expand whistleblower tools so users can report abusive trading on any market.

The new disclosure rule is narrow but significant. Kalshi said it will apply only to markets it deems higher-risk, and the company will use employment information to screen out presumptive insiders before a trade is placed. If suspicious activity appears in the relevant market, Kalshi said it can use that information to help police conflicts. In effect, the company is asking more of traders when the subject matter is more sensitive, a structure that mirrors the conflict checks and restricted-access controls used in traditional financial markets.

Kalshi said the changes were based on the first report from its independent Surveillance Audit Committee, which it created in February to help combat manipulation and insider trading. Robert DeNault, Kalshi’s head of enforcement, said the company was implementing the measures to continue leading the industry on market integrity among federally regulated prediction markets. Kalshi also said the committee will keep issuing quarterly reports, giving the platform a continuing outside review of its own policing practices.

The company pointed to active enforcement already under way. Kalshi said its enforcement team made more than 150 investigations in the first quarter of 2026, blocked more than 100 potential insider trades using new screening tools, made more than 20 referrals to law enforcement or securities regulators, and issued five disciplinary actions. Its policy materials also say the platform has more than 200 historical investigations on its enforcement page and that it proactively screens political figures, sports professionals, certain disqualified persons, and other potential conflicts.

The changes land as prediction markets face sharper scrutiny in Washington. On May 22, House Oversight and Government Reform Committee Chair James Comer launched probes into insider trading on Kalshi and Polymarket, saying lawmakers wanted to understand how the platforms detect anomalous trading and prevent abuse. Kalshi said it looked forward to engaging with the committee and has argued that, as a U.S.-regulated exchange, it already has stronger protections than offshore rivals. The pressure intensified after reports that former Congressman George Santos was under investigation over a trade tied to Donald Trump’s State of the Union, that a U.S. Army soldier was charged with using classified information to make a $400,000 profit on Polymarket, and that a Google employee was charged with fraud after allegedly making more than $1 million with insider information on Polymarket. Kalshi’s new risk-scoring framework adds corporate KPI or event risk, outcome concentration risk, market importance, regulatory compatibility, non-traditional insider risk, and national-security risk, with some low-importance but high-risk markets potentially rejected outright.