US Senate Unanimously Bans Lawmakers from Prediction Market Bets

May 1, 2025 — The US Senate voted unanimously to prohibit senators and their staff from placing bets on political prediction market platforms, including Polymarket and Kalshi. Republican Senator Bernie Moreno authored the resolution, which passed on May 1 and signals growing bipartisan concern over insider trading risks in political event wagering.

Immediate Details & Direct Quotes

The Senate ban applies to all senators and their direct staff, barring them from trading on platforms that offer political event contracts. Moreno, who also set the end-of-May deadline for the CLARITY Act, led the resolution amid increasing scrutiny of prediction market trading by political figures in 2025.

Kalshi confirmed it already proactively blocks members of Congress from using its platform. “This is a great step to increase trust in markets,” the company said, suggesting the resolution formalizes existing industry practice rather than imposing new restrictions.

The resolution emerged from a broader political conversation about whether legislators with access to non-public information hold an unfair advantage on prediction platforms — a dynamic that undermines market credibility designed to aggregate distributed knowledge, according to the Senate resolution.

Market Context & Reaction

The unanimous vote reflects shared concern about insider information advantages, as prediction market data has been shown to move in ways correlating with legislative outcomes before their public announcement. This pattern drew increasing scrutiny throughout 2025, prompting the bipartisan action.

The CFTC has been simultaneously locked in a legal battle with New York, Illinois, Arizona, and Connecticut over prediction market jurisdiction. The Senate vote represents a significant political signal that Congress views political event trading as categorically different from the commercial prediction market activity the CFTC has been defending.

As of today’s vote, the resolution bars senators and their staff from betting on political events on platforms like Polymarket and Kalshi, which had become visible flashpoints after data correlations raised concerns about market integrity.

Background & Historical Context

The resolution emerged amid ongoing CFTC efforts to classify prediction markets on political events as legitimate financial instruments subject to its jurisdiction rather than gambling. The agency has been arguing that these markets represent regulated financial activity, while states have challenged that position.

Moreno’s authorship of the ban carries additional significance: he is the same senator who warned most publicly that the CLARITY Act must pass by the end of May or be shelved until 2030. This connects the insider trading concerns to broader legislative efforts around cryptocurrency and financial market regulation.

The unanimous passage on May 1 represents a rare bipartisan outcome on a financial regulation matter, underscoring the widespread agreement that political event trading by lawmakers creates unacceptable conflicts of interest.

What This Means

The immediate effect is that senators and their staff must cease all political prediction market activity. Kalshi’s proactive block suggests the resolution aligns with existing compliance measures, but the formal ban creates clear legal consequences for violations.

In the short term, other prediction market platforms may follow Kalshi’s lead by implementing similar congressional blocks. The resolution signals to regulators and market participants that Congress intends to treat political event contracts differently from other prediction market categories.

Long-term, this could influence the CLARITY Act deadline and the broader legal framework for prediction markets. The bipartisan nature of the vote suggests potential momentum for additional legislative action before the end-of-May deadline. Market participants should monitor whether the CFTC’s jurisdiction battle with states shifts following this political signal.

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