The United States Senate approved a bipartisan resolution Thursday banning its own members and their staff from placing bets on prediction markets, a rare unanimous move that took effect the moment it passed. The voice vote drew no opposition, as the Associated Press reported, capping weeks of mounting concern that people with access to sensitive government information could cash in on platforms like Polymarket and Kalshi before the public learns what is coming.
Sen. Bernie Moreno, the Ohio Republican who sponsored the resolution, framed the issue in blunt terms:
"United States senators have no business engaging in speculative activities like prediction markets while collecting a taxpayer-funded paycheck, period."
An amendment from Sen. Alex Padilla, a California Democrat, broadened the ban to cover Senate staff, a significant expansion, given that aides often handle classified briefings, draft legislation, and negotiate policy details long before any public announcement. Because the measure was written as a change to Senate rules rather than as standalone legislation, it required no House vote and no presidential signature. It is already in force.
The timeline tells the story. A week before the vote, a U.S. special forces soldier was charged with using classified information to bet on the January capture of Venezuela's then-president, Nicolas Maduro. That case put a sharp point on a problem lawmakers had been circling for months: prediction markets reward people who know things before everyone else, and nobody in America has earlier access to consequential information than members of Congress and their staffs.
Earlier in May, the AP reported that a cluster of new accounts on Polymarket placed highly specific, well-timed bets on whether the United States and Iran would reach a ceasefire on April 7. Those bets produced hundreds of thousands of dollars in profits for the new customers. The timing and specificity raised immediate questions about whether someone with inside knowledge of diplomatic negotiations had used that information to profit.
On the same day the AP published that report, the White House warned its own staff against using private information to trade on prediction markets, a signal that the concern extended well beyond Capitol Hill. The AP noted that the Senate action was driven by fears that lawmakers with access to sensitive information could profit from bets on wars, elections, or other major events.
What stands out is the breadth of support. In a chamber that struggles to agree on naming post offices, this resolution drew zero opposition. Senate Minority Leader Chuck Schumer called it a "no-brainer" and went further, pressing the House and the Trump administration to follow suit.
"We must never allow Congress to turn into a casino where members representing the public can gamble on wars or economic crises or elections. That would destroy the very principle of representative government."
Schumer also urged House Speaker Johnson to adopt an identical rule immediately. Fox News reported that Moreno framed his broader goal as eliminating lawmakers' "side hustles" and rebuilding public trust in Congress, and that even the prediction market companies themselves welcomed the move as a trust-building measure.
The Senate has had no shortage of unanimous votes on narrow procedural matters, but a rules change targeting members' own financial conduct is a different category. It reflects a recognition, belated, perhaps, but real, that the explosion of prediction market platforms has created a new species of insider-trading risk that existing ethics rules never anticipated.
Sens. Todd Young, an Indiana Republican, and Elissa Slotkin, a Michigan Democrat, have introduced a separate bill that would go much further. Their legislation would ban all federally elected officials and government employees from using insider information to make prediction market bets, not just senators and their staff, but House members, executive branch officials, and the sprawling federal workforce.
Young called the Senate resolution "a good first step" and encouraged the chamber to take up the broader bill. The distinction matters. A Senate rules change binds only the Senate. It does nothing to stop a House member, a Pentagon analyst, or a White House aide from placing the same kinds of bets that senators just agreed to forgo.
That gap is worth watching. Congress has a long history of addressing its own ethics problems in the narrowest possible way, passing rules that look good on paper while leaving the larger structural problem untouched. The STOCK Act, passed in 2012 to curb congressional insider trading in equities, is a cautionary example: enforcement has been spotty, penalties minimal, and bipartisan consensus on tougher measures has repeatedly evaporated once the cameras turned off.
The political landscape around prediction markets is more complicated than a clean ethics story. The Trump administration has been described as a key ally of the prediction market industry in its legal fight with states seeking to ban the platforms. Donald Trump Jr. serves as an adviser for both Polymarket and Kalshi. And Truth Social is launching its own cryptocurrency-based prediction market called Truth Predict.
President Trump himself acknowledged the tension this month, telling reporters that "the whole world, unfortunately, has become somewhat of a casino, and you look at what's going on all over the world and Europe and every place, they're doing these betting things." That comment captured the ambiguity of the moment: the administration sees prediction markets as legitimate financial instruments and innovation drivers, while simultaneously recognizing that they create obvious temptations for people who hold government secrets.
The Washington Times reported that the rule change was motivated by concerns about both insider knowledge and public trust, two problems that feed each other. Even if no sitting senator has been caught placing suspicious bets, the mere possibility that they could do so erodes confidence in a body that already ranks near the bottom of public trust surveys.
Polymarket has drawn particular criticism as a venue for offshore trades that operate beyond the reach of U.S. regulators. Kalshi, its chief domestic rival, operates under Commodity Futures Trading Commission oversight but has faced its own scrutiny. Both platforms have issued new insider trading bans amid the growing pressure, a defensive move that suggests the industry understands its vulnerability.
For all the bipartisan back-patting, the resolution leaves significant questions unanswered. The Step 1 material identifies several gaps: the formal resolution number, the specific Senate rule text that was changed, whether the ban covers all forms of prediction-market participation or only certain transactions, and, most critically, what enforcement mechanism or penalties apply if a senator or staffer violates the rule.
A rule without teeth is a press release. If the Senate Ethics Committee is the sole enforcement body, history offers little reason for optimism. That committee has censured exactly one senator in the last two decades. Its investigations move slowly, its proceedings are largely secret, and its membership is drawn from the same body it is supposed to police.
The House has taken no parallel action. Schumer's public call for Speaker Johnson to adopt an identical rule puts the ball in Republican leadership's court, but the House operates under different procedural norms, and Speaker Johnson has his own legislative priorities competing for floor time. Whether the House acts, and how quickly, will be a real test of whether this is a genuine reform moment or a one-chamber gesture.
The Young-Slotkin bill, if it advances, would address the broader problem by statute rather than internal rule. But legislation requires both chambers and a presidential signature, and prediction markets now have powerful allies in the business world and within the administration itself. The path from "good first step" to comprehensive law is long and full of off-ramps.
Give the Senate credit for acting quickly once the soldier's case and the Polymarket reporting made inaction untenable. Moreno deserves credit for sponsoring the resolution, and Padilla's amendment closing the staff loophole was a sensible addition. Unanimous votes on ethics measures are rare enough to be worth noting.
But the harder questions remain. Can Congress extend this principle to the House, the executive branch, and the federal workforce? Will the Senate enforce its own rule with real consequences? And can lawmakers resist the gravitational pull of an industry that is growing fast, spending heavily on lobbying, and now deeply intertwined with figures close to the White House?
The prediction market industry is not going away. Platforms like Kalshi and Polymarket have attracted millions of users and billions in trading volume. The question was never whether these markets should exist. The question is whether the people who write the laws, set foreign policy, and receive classified briefings should be allowed to bet on the outcomes they help determine. On that narrow point, the Senate's answer was unambiguous, at least for itself.
A unanimous vote is easy when the rule only applies to you and the cameras are rolling. The real measure of seriousness will come when it is time to pass a law that binds everyone with a government badge, and actually enforce it.