US Election Trading on Kalshi and Polymarket Jumps 153% to $104M Ahead of the Midterms
Trading quantity on the 2026 midterm elections reached $103.87 million throughout Kalshi, Polymarket US, ForecastEx and Gemini throughout the first 20 days of October, up from roughly $41 million over the identical interval in September.
But the surge wasn’t unfold evenly throughout the November poll.
The Texas Senate race and the battle for management of the House have emerged as the two largest attracts, producing practically $49 million in October buying and selling quantity throughout the 4 operators.
On Kalshi, these two election teams accounted for $29.2 million of the $51.7 million enhance recorded throughout contracts repeatedly noticed in each September and October. That’s greater than half of the progress in the comparable group of contracts, with a whole lot of different election merchandise making up the the rest.
Polymarket US is seeing the same focus. Texas Senate and nationwide House-control contracts recorded a mixed $7.7 million in October quantity, accounting for roughly a 3rd of the operator’s $23.7 million in election buying and selling throughout the interval.
With November 3 approaching, the newest figures present how a handful of races are shaping prediction market trading volume, whilst operators supply contracts overlaying elections throughout the nation.
Texas Senate emerges as October’s largest progress market
Texas Senate generated $17.94 million in October buying and selling quantity on Kalshi, in contrast with $5.96 million throughout the full month of September. The first 20 days of October have already produced thrice September’s complete buying and selling quantity for the race.
The leap can be evident when evaluating equal-length durations. Kalshi’s repeatedly noticed Texas Senate contracts went from $3.53 million throughout September 1–20 to $17.63 million throughout October 1–20.
On Polymarket US, Texas Senate reached one other $3.69 million in October quantity, in contrast with $1.11 million throughout September.
Combined with smaller quantities recorded on Gemini and ForecastEx, Texas Senate generated roughly $21.7 million in buying and selling quantity throughout the 4 operators throughout October 1–20.
The race between Republican Ken Paxton and Democrat James Talarico has attracted way more exercise than most different individual Senate contests. On Kalshi, Michigan Senate generated $4.30 million in October quantity, whereas Ohio recorded $2.49 million and Iowa $2.20 million.
The Texas market has additionally grown sooner than a number of of these contests. Its enhance amongst repeatedly noticed Kalshi contracts exceeded the mixed will increase for Michigan, Ohio, Iowa and South Carolina Senate contracts.
Texas just isn’t merely one of the largest midterm election markets by historic quantity. It is contributing extra new buying and selling exercise in October than some other particular person state election recognized in the information.
Control of the House attracts one other $27 million
The nationwide House-control market generated $26.98 million throughout the 4 operators throughout October’s first 20 days, placing it forward of any particular person state election.
Kalshi accounted for $22.33 million, whereas Polymarket US recorded $4.03 million. ForecastEx and Gemini added smaller quantities.
Kalshi’s House-control contracts generated $7.28 million throughout September 1–20 earlier than rising to $22.33 million throughout October 1–20. That represents a further $15.05 million in buying and selling on the identical repeatedly noticed contracts.
Together with Texas Senate, the House-control market has grow to be a serious supply of the October enhance.
The exercise additionally exhibits the distinction between buying and selling on a single race and taking a place on the nationwide end result. House-control contracts permit merchants to speculate on which occasion will maintain the chamber in any case 435 districts have voted, somewhat than requiring positions in particular person congressional contests.
House management is especially distinguished on Polymarket US, accounting for about 17% of the operator’s October election quantity. On ForecastEx, greater than half of October election quantity got here from the nationwide House-control group, though that market’s total exercise declined in contrast with September.
The national Senate-control market is smaller however rising. It generated $5.05 million on Kalshi and $1.41 million on Polymarket US throughout October 1–20.
Iowa’s governor and Senate races acquire floor
Outside Texas and the nationwide congressional-control markets, Iowa stands out for the progress in its October buying and selling.
Polymarket US recorded $1.44 million on Iowa’s gubernatorial election in the first 20 days of October, in contrast with simply $296,475 throughout the complete month of September.
The enhance was significantly pronounced amongst repeatedly noticed contracts, the place buying and selling climbed from roughly $30,864 throughout September 1–20 to $1.44 million throughout October 1–20.
Iowa’s Senate race is drawing extra consideration as properly. Polymarket US recorded $1.28 million in October quantity, whereas Kalshi generated one other $2.20 million.
The two Iowa elections have now generated practically $5 million in October buying and selling quantity throughout Kalshi and Polymarket US alone.
They stay considerably smaller than Texas Senate and the nationwide House-control market, however their progress exhibits that the enhance is not restricted to the two largest election teams.
Not each election market is rising
October’s positive aspects haven’t been uniform, even amongst established election merchandise.
Kalshi’s Ohio Senate market generated $2.49 million in the first 20 days of October, beneath the $2.71 million recorded throughout the full month of September. Its repeatedly noticed contracts nonetheless greater than doubled over the comparable 20-day September interval.
Other markets confirmed outright declines. Polymarket US recorded $695,028 on California’s gubernatorial election in October, in contrast with $1.06 million throughout September, whereas ForecastEx’s nationwide House-control quantity fell from $500,942 in September to $320,951 in October.
These variations are vital as a result of the trade’s total progress can masks the course of particular person election markets. The October enhance has been substantial, however not each contest is attracting extra quantity at the identical tempo.
The broader figures stay closely weighted towards Kalshi. The operator generated $79 million, representing roughly 76% of the four-operator October whole, whereas Polymarket US accounted for $23.72 million.
Polymarket US, nonetheless, posted the bigger proportion enhance, with election trading volume growing 203% in contrast with the first 20 days of September. Kalshi recorded a 142% enhance.
The subsequent reporting interval will present whether or not the newest progress continues to focus in Texas Senate and congressional-control contracts or begins spreading extra extensively throughout aggressive elections as November 3 approaches.
Methodology: DeFi Rate analyzed noticed election buying and selling quantity from January 1 via October 20, 2026. All quantity is reported utilizing a $1-per-contract or reported-unit conference and doesn’t symbolize money exchanged. October totals cowl October 1–20. Percentage progress comparisons use September 1–20 in opposition to October 1–20, whereas full-September comparisons are recognized individually. Matched-contract comparisons embody solely contracts repeatedly noticed in each durations.
