Senate unanimously bans senators from prediction markets
The U.S. Senate unanimously approved a rule banning sitting senators from trading on event-based prediction markets such as Polymarket and Kalshi; it took effect immediately.
The Senate adopted a resolution that bars sitting senators from entering contracts tied to the occurrence, nonoccurrence or scope of a specific event. The voice vote took place one week after Senator Bernie Moreno introduced the measure on April 24, and the change became effective under the chamber’s Standing Rules.
The resolution amends Rule XXXVII of the Senate Standing Rules to prohibit agreements that depend on specific event outcomes. The language targets event contracts offered by platforms where users trade on elections, legislation, economic releases and geopolitical events. Enforcement will be handled by the Senate Ethics Committee.
An amendment from Senator Alex Padilla narrowed the text to avoid sweeping in conventional financial products, including insurance policies, and to limit the rule to event-based contracts rather than standard financial instruments.
The restriction applies only to sitting senators. It does not cover House members, congressional staff, candidates, executive branch officials or family members of senators, leaving the possibility that those actors could still participate in event markets.
Kalshi chief executive Tarek Mansour welcomed the change and noted his platform already blocks members of Congress and maintains controls against insider trading. He urged the House to adopt a comparable measure, writing, “I applaud the Senate for passing this resolution to ban Senators and their offices from trading on prediction markets… Now, let’s pass this in the House!”
Moreno posted on social media that he was “Proud to say my bill to ban members of Congress from insider trading on prediction markets just passed the Senate UNANIMOUSLY!” He added that “Serving in Congress is an honor, not a side hustle. Americans deserve to know that their leaders are here for the right reason!”
Senate Majority Leader Chuck Schumer praised the resolution ahead of the vote. Because the rule change was adopted as an internal Senate rule, a separate resolution would be required for the House to impose a comparable ban on its members.
The Senate action comes amid several pieces of 2026 federal legislation that would restrict access to prediction markets for broader categories of officials. Supporters of such proposals say they aim to prevent conflicts of interest and insider trading on platforms offering event-based contracts.
Prediction markets allow users to buy and sell contracts that pay out based on the outcome of a defined event. Platforms list markets on topics such as electoral outcomes, legislative actions and economic indicators. The Senate resolution specifically makes those event-based contracts off-limits to sitting senators.
