Which prediction markets saw the biggest moves in the last week?[/B] In the first of our new weekly recaps, professional trader and organizer of Voliti Co's Predict 2026, Tanner Lux, takes a look at the movers and shakers of the past seven days.
A failed legislative vote, new polling and the publication of film reviews changed prediction-market forecasts last week. These five examples capture those revisions, alongside a sports upset.
Kalshi’s probability of the Clarity Act becoming law by year-end fell 23 percentage points on September 15 after a Senate procedural vote failed to secure sufficient support to advance the legislation. Expectations had improved the previous day following reports that President Donald Trump had accepted new ethics provisions.
The vote provided evidence that the revised legislation still lacked the necessary backing. Traders also reduced its longer-term prospects: the probability of enactment before January 2028 fell from 63% to 21%. Because the contracts concerned eventual enactment, the procedural defeat changed the forecast without resolving the market.
Kalshi’s September 15 report.
Bitcoin: Chances of Reaching $85,000 Rise
Market
Previous Probability
Current Probability
Market Move
Bitcoin Exceeding $85,000 Before End of Sep
10%
42%
+32%
The probability of Bitcoin exceeding $85,000 before the end of September rose roughly 32 percentage points between Thursday afternoon and Friday. During that period, Bitcoin advanced from just above $76,000 to approximately $81,099.
The recovery followed a weak start to the week. Bitcoin ETFs also recorded nearly $160 million in Thursday inflows, ending a run of outflows. That buying provided context for the recovery, although it does not establish that ETF flows alone caused it. With Bitcoin still below $85,000, traders were revising expectations for a further advance.
Kalshi’s forecast for Resident Evil’s eventual Rotten Tomatoes score rose from 82% on Monday to 95% by Thursday. The review embargo lifted on Wednesday, allowing critics to publish their assessments.
Early reviews put the actual Tomatometer score at 96%. That gave traders stronger evidence of critical approval than the footage and promotional reactions available beforehand. The distinction matters numerically: this was a 13-point increase in the forecast review score, rather than a 13-percentage-point change in the probability of a particular outcome.
Monday forecast; Thursday update.
Politics: Democrats Strengthen Their Senate-control Lead
Market
Previous Probability
Current Probability
Market Move
Democrats' Probability of Winning Senate
52%
57%
+5%
Democrats’ probability of winning Senate control increased from 52% on Monday to 57% on Thursday on Kalshi. The five-point move was smaller than the crypto swings but extended their advantage after they became the market favorite.
The increase coincided with favorable polling. A Quinnipiac survey showed Democrats ahead 49%–38% on the generic congressional ballot, while a CNN/SSRS Maine survey placed Troy Jackson ahead of Susan Collins, 48%–45%, within the poll’s margin of error. Those findings supplied evidence relevant to Democratic prospects, although the available reporting cannot isolate each poll’s contribution to the price change.
Monday odds; Thursday update.
Sports: New Orleans overturns Baltimore’s advantage
Market
Previous Probability
Current Probability
Market Move
New Orleans Moneyline
-%
-%
-%
The Saints defeated the Ravens 24–17 on Sunday after trailing 14–3. Two fourth-quarter touchdowns and a two-point conversion completed the comeback.
Kalshi’s pregame coverage identified New Orleans as the underdog. Unlike the other examples, the decisive information arrived through play, and the result settled the contract. The upset is documented, but its exact pregame probability and intragame low still require verification before attaching a numerical swing.
Prediction markets involve risk and are not suitable for everyone. While many of the best prediction platforms offer tools to make informed trades, outcomes are never guaranteed, and users should never risk more than they can afford to lose. Always trade responsibly. Additionally, platform availability and legal status vary by region. It is your responsibility to check local laws and verify that you are legally allowed to use a given prediction market platform before participating.
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