Inside Kalshi's ramp

Most of this series has been about the mechanism — how a price becomes a probability, why a market beats a pundit, who decides what's true. This one is about the money. Because the clearest evidence that the category is real isn't a calibration curve; it's an income statement. In three years Kalshi went from a rounding error to one of the fastest-growing exchanges anyone has put numbers to. Here is the ramp, and here is the honest read on what's underneath it.

Start with the line that does the talking. Kalshi's revenue: $1.8M in 2023, $24M in 2024, $263M in 2025.¹ That's a roughly 13× jump, then an 11× jump — two years, two orders of magnitude. Exchanges do not usually grow like this. Exchanges are slow, regulated, network-effect businesses that take a decade to compound. This took about as long as a Series A-to-B.

The model: a toll on volume

How does an exchange make money? Not by taking the other side of your trade — that's a casino, and we spent a whole piece on why this isn't one. Kalshi is a venue. It matches a buyer with a seller and skims a small fee off the transaction. The house has no position; it doesn't care who wins. Its revenue is, to a first approximation, just

The take rate is a fraction of a percent — tiny per trade, by design, because a venue competes on being cheap to trade through. Which means the entire revenue story is the other term. If revenue went up 11× in 2025, it's because volume went up roughly that much. The ramp isn't a pricing story. It's a volume story. So the real question is: where did the volume come from?

What drove it: sports

In July 2024, Kalshi launched sports contracts — markets on who wins the game.⁵ That is the inflection point on the chart. Within months, sports was the overwhelming majority of what traded on the platform, and it has stayed that way: by most accounts sports has been on the order of 80% of Kalshi's volume since mid-2024, and the company's fiscal-2025 revenue came in around 89% sports.⁵ The election markets get the headlines; the football, basketball, and baseball markets pay the bills.

The peak is a clean illustration of the mechanics. On Super Bowl Sunday — February 8, 2026 — Kalshi did on the order of $871M in volume in a single day.⁴ Run that through the model: a low single-digit fee on close to a billion dollars of one-day turnover is real money, on one event, from one game. Multiply that pattern across a full sports calendar and the revenue curve stops looking surprising and starts looking inevitable. The category as a whole rode the same wave — combined monthly volume across the major venues crossed $13B by the end of 2025 and reached roughly $24B by April 2026.⁶

The valuation followed the volume

Private markets noticed. Kalshi was valued at around $2B in mid-2025. In December 2025 it raised $1B at an $11B valuation, led by Paradigm.² Three months later, in March 2026, it raised another round at $22B, led by Coatue.² That's an 11× step in nine months — the valuation re-rating in lockstep with the revenue and the volume beneath it. When the top line is compounding this fast, the cap table tends to keep up.

The honest read

Here is the part the headline numbers gloss over. Today, this is largely a sports-trading business. The revenue is sports revenue; the record day was a sports day; the volume that re-rated the valuation is, overwhelmingly, people trading games. If you came to prediction markets for the dream of a global forecasting utility, the income statement is a splash of cold water: the thing paying for the dream is, right now, closer to a leaner, exchange-traded cousin of a sportsbook.

I think that's fine — as long as you say it plainly. Sports is the liquidity engine. It's the high-frequency, high-volume, always-on activity that funds the operation, fills the order books, and builds the regulated rails. What sits on top of those rails — the forecasting, the hedging, the live event data — is the option value. And it's worth being precise about which one the smart institutional money actually bought.

What the ramp says about the category

Two things, beyond Kalshi itself. First: the unit economics work. A tiny take rate on enormous, recurring volume is a genuinely good business — the same shape as every successful exchange in history, just compressed into a couple of years. The question of whether anyone would pay to use these markets has been answered, emphatically, by people betting on football. The forecasting use cases don't have to carry the cost of the rails; the trading already does.

Second: winner-take-most is visibly playing out. Exchanges concentrate, because liquidity attracts liquidity — the venue with the tightest spreads pulls the next trader, which tightens the spreads further. Kalshi's lead, and the valuation gap that has opened behind it, is what that network effect looks like from the outside. We pulled apart why liquidity compounds in the market-maker problem; the ramp is that theory showing up in a funding announcement.

None of this settles whether prediction markets become the probability layer of the internet or stay a very good business for trading sports. But it does settle one thing: the standing-start phase is over. The volume is real, the revenue is real, and the rails are being built — paid for, for now, by the games. What gets routed over them next is the actual story. We'll keep telling it.