Kalshi adds accuracy scores and trade feeds to election markets

Kalshi has added low-volume labels, Brier scores and prominent real-time trade feeds to its U.S. midterm-election markets, seeking to show users both how actively a contract is trading and how its probabilities have performed against eventual results.

The features went live Oct. 6, less than 30 days before the general election. Kalshi said the changes were designed to give traders more information about market activity and accuracy: on its midterm markets, it said, viewers outnumber traders five to one.

The exchange now labels election markets with less than $10,000 in trading volume as low-volume and displays the total volume. The distinction matters because experts have warned that thinly traded prediction markets can produce sharp price swings and wider gaps between buy and sell prices.

Kalshi said its historical low-volume markets have Brier scores comparable with leading human forecasters, whose competition scores are typically around 0.1. A lower Brier score indicates a more accurate forecast. The company calculates the measure from millions of historical data points, weighting results by trading volume and how close a market was to resolution.

The activity feed, previously lower on individual market pages, has been moved to a more visible position. It shows each trade as it occurs, allowing visitors to follow changes in a market probability trade by trade.

Kalshi said the tools respond in part to traders participating in markets on local contests more than national races. The company provides live midterm contracts for every U.S. Senate, House and governor race, and in July introduced a Midterms Hub combining its odds with polling averages, campaign-finance data, past presidential results and campaign news.

The company described 2026 as the first midterm election in which prediction markets had become mainstream. It said election-trading growth this year was six times faster than growth in football trading, and that three-quarters of its users do not trade at all. Total visits to its midterm markets were 50 times the number of traders, Kalshi said.

Tarek Mansour, Kalshi's chief executive and co-founder, called the midterms the “first meaningful prediction market election.” Kalshi maintains that its probabilities result from participants trading against one another, rather than from polls or odds set by a bookmaker.

As our earlier report noted, Kalshi has also faced concerns from Michigan and election officials that its election contracts resemble gambling and could create risks of manipulation or insider trading. The exchange said it is regulated by the Commodity Futures Trading Commission and bars candidates, campaign workers, election officials, pollsters, media decision desks and other people able to influence a race from trading on it.

Kalshi said every account undergoes identity verification, while suspicious timing or coordinated activity can trigger a freeze and investigation. It said it had fined and suspended four congressional candidates in 2026 for trading on their own contests.

Its election contracts settle only when at least four of eight major news organisations call a race without any of the eight disagreeing. A contract remains open through a recount or legal challenge until the winner is sworn in.

Kalshi has also partnered with the Associated Press to show live vote counts and race calls beside its forecasts. CBS News planned to feature Kalshi markets alongside its polling in midterm coverage, while 270toWin planned to display the exchange's forecasts with live election results.