Kalshi has added 3 million new users over the course of the 2026 World Cup, according to CNBC, a customer land grab that has turned the tournament into the single biggest event in prediction market history. More than $1.2 billion has traded on the Kalshi World Cup winner market alone, a record for a single contract, and the Argentina vs Spain final that kicks off Sunday has already blown past it.

Within days of going live, the final’s contract surpassed $1.27 billion in trading volume, making it the largest individual market Kalshi has ever hosted, Fortune reported. As of Friday, Kalshi traders gave Spain 61% odds to beat Lionel Messi’s Argentina. Across all platforms, World Cup trading has exceeded $29 billion, and CoinDesk reports prediction markets collectively topped $50 billion in monthly volume during the tournament’s first month. For a product category that barely registered two years ago, the question is no longer whether prediction markets arrived. It is whether they can keep the crowd they just won.

The Numbers Behind the Kalshi World Cup Surge

In June alone, Kalshi posted $31 billion in total notional trading volume, a more than 70% jump from May, with sports contracts accounting for roughly 85% of activity, according to Dune Analytics data cited by CoinDesk. The company says Kalshi World Cup volume across all tournament contracts has reached $22.42 billion.

Compare that with the benchmarks that used to define big. The NBA Finals generated about $2 billion in prediction market volume this year. The Super Bowl did about $1 billion. The World Cup winner market beat both before the group stage even ended, generating $7.4 billion on Kalshi in June alone.

“Our volumes are where the news is at,” Kalshi CEO Tarek Mansour told CNBC. Asked whether activity collapses after the final, Mansour argued the cycle repeats itself: “You have to believe there’s not going to be any news after Sunday. Maybe. But the more probable thing is that there’s going to be like a bunch of things going on in the world, and Kalshi’s going to be there to service it.”

Rivals rode the same wave. Polymarket’s international exchange set a monthly record of $10.8 billion in overall volume while its regulated US platform logged $3.5 billion, nearly double May’s total. Its World Cup Winner market has generated $4 billion since launching in July 2025, the largest market in Polymarket’s history, bigger even than the 2024 US presidential election. If you are weighing the two platforms, our Kalshi vs Polymarket comparison breaks down fees, regulation, and market depth.

Why Is the Final the Biggest Prediction Market Ever?

Three forces converged. First, the tournament came to American soil with prime time kickoffs, and the US team’s run to the round of 16 pulled in casual fans who had never bet on soccer. Second, 39 states now have legal mobile sports betting, up from 19 in 2022, normalizing the behavior prediction markets monetize. Third, Kalshi bought its way into the broadcast. The company signed a co-branding partnership on June 26 with ADI Predictstreet, the World Cup’s official prediction market partner, giving it branding rights, in-venue presence, and a media distribution deal with Fox Sports. Kalshi and Polymarket ads ran during halftime and even during hydration breaks.

All that marketing landed on an audience already primed. App intelligence firm Apptopia found Kalshi’s daily active users on June 30 were 36% above their June 15 level. Kalshi and Polymarket together captured 78.5% of betting app installs across the six major platforms Apptopia tracks through June. A year earlier, the two combined for roughly 6% of that audience.

Sportsbooks Spiked Early, Then Faded

Traditional sportsbooks had a record tournament by their own standards. Gaming research firm Eilers and Krejcik projected US legal sportsbooks would handle between $2.8 billion and $4.3 billion across the 104 matches, and operators say results beat their most optimistic forecasts. The US vs Belgium round of 16 match became the most bet soccer game in the history of several major American books, and at Caesars, 81% of US knockout round handle rode on the Americans.

“This World Cup has been record-type handle stuff for us this whole time,” BetMGM’s Christian Cipollini told ESPN. DraftKings reported handle running at roughly five times its 2022 World Cup levels.

But the trajectory diverged sharply from the prediction markets. Per Apptopia, DraftKings’ daily active users fell 36% from their tournament peak by June 30. FanDuel dropped 41%. BetMGM and Caesars each declined 32%. Sportsbook apps spiked early and faded, while the Kalshi World Cup markets built steadily through the knockout rounds. More telling still, Apptopia found sportsbook users increasingly sampled Kalshi during the tournament while the share of Kalshi users opening sportsbook apps declined. The theory that prediction markets would feed customers to traditional betting has not held. The flow runs the other way.

The New Bettors Nobody Saw Coming

Demographic data may matter more than the volume records. Kalshi’s female user base grew 106% during the tournament, more than double the 54% growth among men. By late June, 33.3% of Kalshi’s users were women, compared with 22% to 23% at DraftKings and FanDuel. Some of that surge traces to Kalshi’s reality TV markets on shows like Love Island, Barron’s reported, but the World Cup accelerated it. Kalshi is pulling in people who never touched a sportsbook.

Brand tracking tells the same story. YouGov’s BrandIndex found Kalshi was the only betting adjacent company among the brands gaining the most consumer momentum during the World Cup, out of more than 2,000 tracked. It shared that list with Coca-Cola, Pepsi, and Visa, and outranked Fox, the tournament’s own broadcaster.

Wall Street Joins the Party

Institutional money followed the retail wave. DRW, the Chicago trading giant, has been building a dedicated prediction market desk targeting Kalshi and Polymarket, applying cross-platform arbitrage techniques honed in traditional derivatives. The near identical World Cup odds across Kalshi, Polymarket, and the major sportsbooks reflected sharp money closing gaps as they opened, a sign the markets now carry enough liquidity for professionals to treat prices as credible.

New competition arrived mid-tournament too. Rothera, the joint venture between Robinhood and Susquehanna International Group, launched in June and processed $2 billion in notional volume in its debut month, already 7% of the US prediction market, according to Bank of America. For readers new to the category, our guide to how prediction markets work covers the mechanics.

Can Kalshi Keep 3 Million New Traders?

Here is the problem hiding inside the celebration: volume on days without World Cup matches has been significantly lower than on match days, per CNBC. Kalshi’s challenge is converting tournament tourists into recurring traders of election, economic, and entertainment contracts before the soccer high fades.

History offers Kalshi a mixed precedent. The platform saw a comparable surge around the 2024 election followed by a pullback, then growth resumed on new event cycles, which is the pattern Mansour points to. Skeptics note soccer’s four-year cycle is unlike an annual NFL season. The 2027 events calendar has no single moment remotely this size, and retention economics in betting adjacent apps are notoriously brutal.

Accuracy is a second open question. Kalshi and Polymarket priced both semifinals wrong, giving roughly 10 point edges to France and England, the eventual losers, before kickoff. Earlier rounds were kinder to the markets: Kalshi priced France at 76% over Morocco and Spain at 73% over Belgium, and both favorites advanced. Sports remain a harder forecasting problem than elections or Fed decisions, where slower moving information gives markets their edge.

Regulators Are Watching the Boom

Growth this fast draws scrutiny. Congress has already probed insider trading concerns at the major platforms, detailed in our coverage of the Comer investigation into Kalshi and Polymarket. Just this week, a White House teleprompter operator was placed on unpaid leave over allegations of $100,000 in insider trades on Kalshi. The CFTC, meanwhile, has moved to draw bright lines around what event contracts can cover, banning markets on terrorism and assassinations under rules finalized earlier this year.

A jurisdictional wrinkle hangs over the boom, one the industry would rather not discuss. Onchain analysis firm Allium found US linked wallets traded $571 million on Polymarket’s offshore political markets over the past year, more than any other country, despite geoblocking, evidence that VPN traffic still routes around the regulated US products. About 11 states continue to contest sports event contracts on Kalshi. How regulators reconcile state gambling law with CFTC jurisdiction remains the industry’s biggest unresolved risk, and every new user Kalshi adds raises the stakes of the answer.

Frequently Asked Questions

How many new users did Kalshi add during the 2026 World Cup?

Three million, according to CNBC. Apptopia data shows Kalshi’s daily active users on June 30 were 36% above mid-June levels, while major sportsbook apps declined 32% to 41% from their tournament peaks over the same stretch.

How much money was bet on the World Cup final on Kalshi?

Trading on the Argentina vs Spain final contract surpassed $1.27 billion within days of launch, making it the biggest single market in prediction market history. As of Friday, Kalshi traders priced Spain at 61% to beat Argentina. Overall Kalshi World Cup volume has reached $22.42 billion.

Is Kalshi bigger than DraftKings or FanDuel now?

Not in revenue, but momentum shifted during the World Cup. Kalshi and Polymarket captured 78.5% of betting app installs across the six major platforms through June, versus roughly 6% a year earlier. Sportsbooks still handled a projected $2.8 billion to $4.3 billion on the tournament, and DraftKings’ handle ran five times its 2022 levels.

Are Kalshi World Cup predictions accurate?

Mixed. Markets priced earlier rounds well, but both semifinals went against the pre-match favorites, with Kalshi giving roughly 10 point edges to France and England, who both lost. Sports outcomes are inherently noisier than elections or economic data, where prediction markets have shown stronger forecasting records.

Who competes with Kalshi in prediction markets?

Polymarket is the main rival, with a record $10.8 billion in international volume in June plus $3.5 billion on its regulated US platform. Rothera, a Robinhood and Susquehanna joint venture launched in June, already holds 7% of the US market. Startups like Pascal are also raising capital to enter the space.

Is trading on Kalshi legal in the United States?

Yes. Kalshi is a CFTC regulated Designated Contract Market, the same legal status held by major futures exchanges. However, roughly 11 states contest its sports event contracts under state gambling law, and the CFTC has banned certain contract types, including markets on terrorism and assassinations.