Kalshi expanded its “combo” event contracts product to all users Monday in a move that expands the lucrative offerings and raises the stakes on the growing prediction market industry.
- Kalshi expanded its combo event contracts to all users, allowing multiple outcomes in one contract that mirrors sportsbook parlays.
- The product strengthens Kalshi’s revenue potential and first-mover advantage as FanDuel, DraftKings, and Fanatics race to launch similar offerings.
- The expansion comes amid escalating legal challenges, with states arguing sports event contracts are illegal gambling subject to regulation.
Kalshi combos allow users to stack multiple outcomes within a single event contract. These combined bets offer customers higher payouts if all outcomes are correct, but results in a loss for the user if any are unsuccessful.
These replicate sportsbooks’ parlays, which have higher profit margins than traditional straight bets and constitute an increasing percentage of operators’ revenue. Despite the lower success probability, customers continue to flock to these bets, drawn by the potential to turn small wagers into large payouts.
By offering combos, Kalshi now has an event contract sought by customers that doubles as a powerful revenue generation tool - and creates greater urgency among its competitors to create a similar product.
Sportsbooks look to catch up
Kalshi was among the prediction markets that began offering sports event contracts earlier this year and subsequently accrued hundreds of millions of dollars in trading volume. Seeing the massive revenue potential, the nation’s three highest-grossing sportsbooks - FanDuel, DraftKings and Fanatics - announced prediction market launch plans.
The sportsbooks feared they would fall behind in the prediction market race as Kalshi as well as competitors Polymarket, Crypto.com, Robinhood, and others launched their own platforms. Underdog, which had originally pursued real-money sports betting licenses in multiple states, has shuttered its sportsbook platform to focus on prediction markets.
Like parlays, all operators see combination event contracts as critical to their long-term success.
The wait is over: Combos are officially live for everyone on Kalshi!
— Tarek Mansour (@mansourtarek_) December 15, 2025
Last week alone they did over $100m in volume.
And it's compounding: our app grew 50% in November and we hit another volume record yesterday ~$340m.
In traditional financial markets, traders bundle multi-leg… pic.twitter.com/mtKMYIbqDj
Fanatics launched its prediction market platform earlier this month with FanDuel and DraftKings set to follow in the coming weeks. None have matched Kalshi's combos so far, giving the company an advantage over its growing competition.
Risks ahead
The combo expansion comes as all sports event contract proprietors face growing legal jeopardy.
Kalshi headlines a list of prediction market companies facing court battles in multiple states. Gaming regulators in a growing number of jurisdictions view sports event contracts as an illegal form of gambling. The prediction markets counter that these contracts are governed by federal commodities regulations and not subject to state-level oversight.
Industry observers believe the legal challenges will continue for years, likely until the Supreme Court makes a final determination.
The sportsbook operators-turned prediction markets could also face a separate wave of legal challenges.
FanDuel, DraftKings, Fanatics, and Underdog only plan to offer their prediction markets in states where they don’t offer real money sports betting. This, the operators believe, means they are not in violation of their existing sportsbook licenses.
But several states have warned these companies that offering sports event contracts could jeopardize their licenses for other gaming offerings. Arizona this month became the first jurisdiction to take action, moving to strip Underdog of its daily fantasy sports license due to its affiliation with Crypto.com, which had previously offered sports event contracts in the state.
The pending prediction market launch by FanDuel and DraftKings, which accepted roughly $100 billion in legal sports bets last year, could up the stakes of regulatory action.
That is a risk the nation’s leading sportsbook operators increasingly feel they need to take. These operators fear Kalshi’s first-mover advantage on sports event contracts may become too much to overcome - just like FanDuel and DraftKings achieved with their daily fantasy sports platforms more than a decade ago.
Kalshi's move toward combos raises these stakes. FanDuel and DraftKings officials believe it will be several months after launching before they’ll have the capability to offer a similar parlay-type product.
In the meantime, Monday’s full-scale combo rollout continues to give Kalshi a significant advantage in what is becoming an increasingly intense race for a rapidly growing market.
