Kalshi One Year Later: Still Mostly Sports, Now Mostly Parlays

Sports made up about 82% of Kalshi's trading volume in the first nineteen days of September 2026, and parlays alone made up 56%. Those figures come from a GuardianBlock count of every market in Kalshi's public data feed that closed between September 1 and September 19, 2026: about 35.1 billion contracts, or roughly 1.85 billion a day. Crypto contracts accounted for about 15%. Everything else on the exchange, from elections to the weather, accounted for about 2.4%.

These numbers count contracts traded. They do not count dollars wagered or lost, and for parlays that difference is large. The method and its limits are set out below so the figures can be checked.

How much of Kalshi is sports?

The number most often repeated comes from Sportico, which reported in October 2025 that sports was about 90% of Kalshi's volume from September 1 to September 28, 2025. The NFL was $1.13 billion of it, about 42%, and college football $811 million, about 30%. Non-sports markets came to $276 million. Sportico's charts credit Kalshi as the source of the data.

One year later, the same weeks look different. In markets closing September 1–19, 2026, sports was 82.5% of contract volume: 9.3 billion contracts in single-event sports markets plus 19.7 billion in parlays built entirely from sports legs. The share moved with the football calendar. It was about 90% across the five Saturdays and Sundays in the window and about 78% on the fourteen weekdays. Day by day it ran from 74% on Wednesday, September 16 to 91% on Saturday, September 12.

The two figures are not a matched series. Sportico's covered 28 days and used data Kalshi supplied; this count covers 19 days, holds only the opening week and a half of the NFL season, and uses the method described below. A third figure is different again: Pew Research Center, using data from The Block, put sports at 80% of Kalshi's volume across July 2024 to early May 2026. That is a two-year average, not a snapshot.

The larger change is inside the total. Set parlays aside and sports was only 60.7% of the volume in single markets, with crypto at 34.3% and everything else at 5.0%. Among single sports markets, tennis drew the most contracts (3.3 billion), ahead of Major League Baseball (1.6 billion), college football (1.5 billion), and the NFL (0.8 billion). Sports did not shrink on Kalshi. Most of it moved into parlays.

How big are Kalshi parlays?

Kalshi calls its parlays combos. In the exchange's own words, combos “resolve to the product of the underlying positions, paying out a maximum of $1.00 per contract.” Every leg has to win for the contract to pay in full.

They were new a year ago. The same Sportico article reported that custom parlays had launched that week and seen $255,757 in volume. By the first week of November 2025, Sportico reported, they were a little over $30 million of more than $1 billion in weekly volume, about 3%.

In markets closing September 1–19, 2026, combos were 19.8 billion of 35.1 billion contracts, or 56.4%. Daily, their share ran from 47% to 66%. Industry analysts reached similar readings first: The Closing Line reported on August 31 that about half of Kalshi's volume was parlays, and The Event Horizon, using TickerTracker data, put combos at $2.97 billion of $4.89 billion, or 61%, over the weekend of September 12–13.

Reading the legs of every combo adds two details. First, they are almost entirely sports: 99.3% of combo volume sat in combos whose every leg was a sports market, and combos with only crypto legs or a mix of categories were under 1%. Second, they are long. More than half of combo volume sat in combos of ten legs or more, and about 49% in combos of eleven or more. Baseball was the most common ingredient: 29.6% of combo volume included at least one MLB game-winner leg, against 12.0% with at least one NFL game-winner leg.

What the research says about parlay tempo on sportsbooks is covered in Why Parlays, Props, and In-Play Bets Hit Differently.

What is Kalshi's 15-minute Bitcoin market?

Most of what is not sports is crypto, and most of the crypto is one product. Kalshi's “Bitcoin price up down” series asks whether Bitcoin's price will be higher at the end of a fifteen-minute window than at the start. A new market closes every fifteen minutes, 96 times a day, including overnight and on weekends.

That single series accounted for about 3.96 billion contracts in the window, 11.3% of all volume and more than every non-sports, non-crypto market combined. Crypto as a whole was 15.1%. The Event Horizon's data for one day in late August, August 25, 2026, had crypto at 19.3% of Kalshi's volume. This count's method favours very short markets, as the method section explains, so its crypto share is best read as an upper-side figure.

Why contract volume is not money wagered

Kalshi's public data counts volume in contracts. Each contract pays $1 if it wins, and a matched contract is counted once. A contract bought for fifty cents and a contract bought for two cents each add one to the total. A long parlay is cheap because it rarely pays, so a small purchase of long-odds combos produces a large contract count.

Sportico attached the same warning to the original 90% figure, writing that volume “includes trades involving institutional market makers and over-counts each individual's risk” and “is not interchangeable with traditional sportsbook handle.” Volume also counts a position twice when it is opened and later sold. None of these figures says how many people trade on Kalshi, how much they deposit, or how much they lose.

How this count was made

• Source: Kalshi's public market-data feed, which requires no account. It was read on September 20, 2026.
• Window: every market whose closing time fell on one of the nineteen Eastern-time days from September 1 to September 19, 2026. About 1.4 million single-market records and 23.6 million combo records were read; 12.3 million combos had traded.
• Measure: each market's lifetime contract volume, counted on the day the market closed.
• Categories: Kalshi's own category for each market series. Kalshi files the combo series under its own “Exotics” label, so each combo was classified by the categories of its legs instead. Counting every combo as sports, the simpler convention, gives 82.9% rather than 82.5%.
• Cross-check: on the three days with published daily totals, this count ran somewhat above them, which is what counting a market's whole life on its closing day would produce. The parlay shares agree closely.

The closing-day method has a known tilt. It leaves out markets that were still open on September 20, such as season-long futures and elections, and it gives long-running markets no credit until they close. It gives full credit to markets that open and close inside the window, above all the fifteen-minute crypto contracts. The “everything else” share of about 2.4% is therefore a lower-side figure, and the crypto share an upper-side one. A count by trade date, or over a full month, would move the numbers somewhat. Sports would still be most of the total.

Kalshi outside the exchange

Volume is one measure of reach. Placement is another. Yahoo Fantasy's matchup screen now labels its win-probability bar “Win% presented by Kalshi.” That is a fantasy-football screen, not a trading screen; the label was there on September 20, 2026, in NFL Week 2.

Whether these contracts are gambling is a separate, unsettled legal question, covered in Is Kalshi Gambling?. The age and consumer-protection rules that apply are covered in Kalshi, Young Adults, and the NFL. For an adult who has decided these sites are personally off-limits, How to Block Kalshi and Polymarket on Windows explains what a website block on a Windows PC does and does not cover.