Kalshi posted $2.94 billion in trading volume last week. That was the second-biggest week in its 271-week history, behind only the week of July 2, when volume hit $3.07 billion. But the burst in activity barely changed what people thought across most of the exchange. Alea Research said the market that truly got repriced was the Federal Reserve contract tied to the September 16 decision.
In that market, the odds of a 25-basis-point rate hike climbed from 45% to 55% over the week. The odds of no change dropped from 55% to 45%. The two contracts crossed midweek. Then came the data. After producer price numbers landed on September 10, the hike contract finished that day at 63%. After consumer price data on September 11, the bid stood at 81% and the ask at 82%.
Election markets were quiet even as exchange volume surged
Most election contracts hardly budged. The Republican House contract closed at 16% and has stayed inside a 5-point band since July. It also held between 14% and 17% through all of August. The Senate contract closed at 53%, and Texas closed at 51%. Both sat near their opening levels and roughly where they were a month ago.
Those contracts do not settle until November 2026. Alea Research said there was no date-specific news event hitting those markets, so prices mostly sat still. The gap versus the Fed market was stark. Since July, the House contract moved across 5 points. The Fed contract covered 55 points.
Energy-driven inflation data pushed rate-hike pricing higher
The report tied the Fed repricing to two inflation releases driven by energy. The Bureau of Labor Statistics said diesel prices jumped 24.1% in August and made up more than one-third of the rise in goods producer prices. Gasoline rose 3.9% and was blamed for more than one-third of the monthly consumer increase.
Oil sat at the center of it. WTI crude climbed from $70.56 on June 30 to $97.26 on September 9. But the report also laid out an older, simpler rival explanation. At Jackson Hole on August 28, Chair Warsh said better summer inflation readings "do not tell me that the underlying trend has materially improved." That day, the contract leapt from 30% to 50%, before either of the later inflation prints had arrived.
Exchange growth was real, but it was not broad-based
Kalshi’s total exchange volume rose 12.3% from the prior week. Still, the gains were packed into a few areas. Parlays jumped 18.8%, and sports rose 11.2%. Together, they made up 83% of the venue’s total volume. Election volume fell 32.8%, technology dropped 26.7%, and entertainment slid 17.4%.
Open interest painted a different picture. Election trading volume fell by one-third, yet those markets still added 3.83 million positions. Economic markets were down 8.8% in volume but added 8.73 million positions. Alea Research called that mix accumulation. Quiet, but heavier. In its view, the markets with predictive value were getting less active and more loaded up at the same time.
One name, two very different Kalshis
The report argued there is a fast Kalshi and a slow Kalshi, and every headline number mashes the two together. The fast version revolves around parlays and 15-minute crypto markets. A parlay on Kalshi bundles multiple outcomes into one ticket and pays only if every leg hits. That product works a lot like what sportsbooks sell, except it is listed as an event contract.
The combined contract is not priced like a simple multiplication of its legs. Republicans winning the House traded at 16%, and Republicans winning the Senate traded at 53%. Multiply them and you get 8.5%. But the contract bundling both outcomes traded at 18%, more than twice that level, because the market treated both elections as one bet on the same national swing.
Kalshi puts parlays inside its Exotics category. Last week, Exotics made up 54.3% of total volume, while 15-minute Bitcoin markets added another 11%. Those contracts open and settle within a day. The slow Kalshi—election and economic markets—accounted for only 0.4% of trading volume but 31% of all open interest at the weekend close.
Using volume divided by open interest as a turnover measure, crypto turned over 85 times per week, parlays 25 times, and elections 0.1 times. That is slow. Really slow. At that pace, the election board changes hands about once every 10 weeks. Traders buy a view on the midterms, then just sit on it.
The 147 million increase in open positions was not mainly a weekend-gambler story
Traders added 147 million open positions last week, the fourth-largest weekly build in Kalshi’s history. The easy guess would be weekend parlay traffic. Alea Research said that guess misses the mark.
Exotics added 101 million open positions in total. Break that apart and the picture splits cleanly in two. One combo-contract series traded 6.41 billion contracts, more than half of the whole exchange total, yet ended the week with 28 million fewer open positions than it began with. Another combo-contract series traded 223 million contracts, just one twenty-ninth as much, but added 129 million open positions. That second series by itself accounted for 88% of the exchange’s entire open-interest build.
Alea Research said the record build was not driven by short-term weekend bettors. It came from a slower product that people were buying and holding. Outside of that, sports-calendar markets also added to the total: the Super Bowl added 9.13 million, the Heisman Trophy 6.36 million, and the College Football Championship 6.22 million.
Dollars and contract counts moved at different speeds
Kalshi reports both dollar trading volume and the number of contracts traded. Last week, those two gauges split apart. Dollar volume rose 6.6%, while contract volume climbed 12.3%. So the average contract got cheaper, slipping from 25.4 cents to 24.1 cents.
The report said long-shot legs often trade for only a few cents. Tiny prices. Big counts. That means they can push contract volume up much faster than they push dollar turnover. Which is why contract volume can make Kalshi look stronger than dollar volume does.
The biggest day of the week was Saturday, September 5, when $509 million traded during the college football opening slate. The slowest day was Monday, September 7, at $346 million. Even then, Kalshi’s quietest day last week still beat the best day from a year earlier.
Alea Research also said fees for Kalshi event contracts follow a quadratic relationship with price. Fees are charged on expected contract payoff, peaking near 50 cents and falling off toward both ends.
Perpetuals notional volume ran at 1.8 times event-contract cash volume
Kalshi also runs perpetual futures, leveraged contracts that track asset prices without an expiry date. The exchange launched the first U.S.-listed perpetual contracts on May 29, and notional volume cleared $1 billion in the first week.
Across 13 perpetual markets with full history in both comparable weeks, notional trading volume reached $5.24 billion, up 13.2%. That compares with $2.94 billion in cash trading volume on the event-contract exchange. Bitcoin and Ether accounted for 91% of perpetual activity.
New listings this week included gold and silver perpetual futures, launched on September 10. The report said both had CFTC approval and traded around the clock. Kalshi’s stated argument was that the futures structure "was designed for physical delivery of wheat and corn," while most participants never want delivery and instead pay roll costs for an expiry they do not need. By the end of the week, neither metals contract had traded.
The exchange also rolled out a full slate of UEFA Champions League series. Of the 292 series that traded this week but not last week, 20 were Champions League listings. Five perpetual contracts had no comparable prior week and together traded $59.8 million.
What Alea Research is watching next
The report closed with four dated items and a promise to track the outcome.
- September 16: the Federal Reserve. The contract showed an 81% probability of a rate hike. Alea Research called this the first calibration test worth scoring, saying a missed 81% says more than a correct 81%.
- September 16: the metals fee schedule. It could take effect as early as that day’s close. Gold and silver have not traded since listing on September 10, so the next issue is whether activity starts.
- Next week: the soccer book. The 12 largest open-interest positions settling next week are all soccer parlays, and 10 of them are priced below 3%. The report said it will be worth watching whether the book keeps expanding after the football opening weekend passes.
- October 14: the next CPI release. Alea Research said the chain driving the Fed contract runs through energy. If crude stays near $97, the next print would bring the same push.
Alea Research also said it is recording the weekly prices of every market settling between September 11 and September 18 and will report next week on how the crowd performed.
