It took only two days of voting for the College of Cardinals to elect a new pope—a scenario prediction markets, in the days leading up to the conclave, saw as entirely plausible. Traders on Kalshi gave roughly a 50% chance that a new pope would be chosen before May 9 and around 25% chance it would take just 3 to 4 rounds.
What they didn’t see coming was who would walk out as pope. Even after white smoke rose from the Sistine Chapel, traders doubled down as the betting favorite’s odds surged — but it was a 99-to-1 longshot who emerged on the balcony. Once again, the conclave reminded everyone that the market isn’t omniscient.
While traders may have missed, prediction market platforms Kalshi and Polymarket certainly did not.
Pope markets break $40 million in trades
Kalshi’s market launched on April 21, just hours after the death of Pope Francis. In merely two and a half weeks, the market facilitated $10.6 million in trades.
“The papal market was wildly successful on Kalshi as expected, and the secretive nature of the event provided a great opportunity for savvy traders to win big,” a Kalshi representative told PredictionNews.
Polymarket, which launched its pope market in February ahead of Francis’ death, generated a whopping $30 million in trades. In addition to its longer lifespan, Polymarket is available to traders around the globe, while Kalshi serves only users inside the U.S.
It’s also unclear to what extent Polymarket is actively prohibiting U.S.-based users. Either way, the platform’s international accessibility likely contributed to its higher volume, especially for an election that involved 133 candidates from across the world.
Kalshi’s four other pope-related markets—such as How many rounds will it take to elect the new pope? and What will the next pope’s name be?—saw relatively modest activity, with trading volumes in the low six figures. In total, these supplemental markets added a little more than $600,000 in volume.
When the smoke went white, Kalshi went dark
Not all was rosy at Kalshi, though. In the minutes leading up to and following the white smoke, Kalshi’s site experienced technical difficulties for a significant period—an inopportune time for traders hoping to cancel open orders or capitalize on the moment.
“The Kalshi site was temporarily down today. We have now identified and resolved the issue, and it should not be a problem going forward,” a Kalshi representative told PredictionNews.
Users, including a top prediction market trader known by the pseudonym Domer, aired their frustrations in Kalshi’s public Discord channel. “My support request is to please fix the website before you guys write more self-congratulatory tweets about an event that your website was down for,” Domer posted.
The technical issue not only left some traders in a difficult position but also prevented numerous trades from going through during the brief window between the appearance of white smoke and the pope’s public reveal.
Market miss: Grading pope predictions
"He who enters the conclave as pope, leaves it as a cardinal."
For prediction markets, this conclave was a masterclass in humility. Despite real-time price action and massive trading volume, few saw the eventual pope coming.
Who knows if Cardinal Parolin, the betting favorite, was as confident in his papal prospects as traders were when they priced him around 30¢. With conventional wisdom suggesting that an early consensus would likely land on a papabile like Parolin or Cardinal Tagle, his odds surged to around 70¢ after white smoke appeared.
But the Holy Spirit, it turns out, is more unpredictable than U.S. elections, which prediction markets correctly forecasted last fall.
When the pope was unveiled, it was Cardinal Robert Prevost, now Pope Leo XIV— which the markets also missed on, never giving ‘Leo’ more than a 12% chance of being the next pope’s name.
A surprise pick from Chicago, Prevost was priced at 1¢ (+9900 in American betting odds), odds that paid handsomely to the few traders who bet on the longshot becoming the first American pope in history.
For a deeper dive into why the market forecasted the election so poorly, check out Chris Gerlacher’s piece here.
Big wins
The market may have missed, but a few traders saw value on the American cardinal.
One user on Polymarket, JustPunched, who is presumed to be the prediction market trader “Domer,” took a big position on Prevost leading up to the reveal, netting $66,905 in profits in the market.
Meanwhile, here were some of the biggest wins on Kalshi:
Takeaways
There are a few lessons worth drawing from this historic papal market.
First, prediction markets are not always crystal balls. They reflect the consensus of traders, and in this case, that consensus was off due to the secrecy of the event. But that doesn’t make them useless—far from it. Beyond acting as forecasting or financial instruments, prediction markets are also useful precisely because they force people to put their money where their mouths are.
Also, for those wanting to know who the likely papal contenders were, was there something better to look at than prediction markets? As economist Jason Wolfers said:
"The promise of prediction markets isn’t that they’re perfect, it’s that everything else is worse."
Second, this event was a reminder of the importance of competition in the U.S. prediction market space. Kalshi deserves credit for launching creative markets around the conclave that were available to U.S traders, but its hefty fees, which were as high as 6%, and infrastructure—especially the site going down during the most critical moment—highlight why a single platform isn’t enough. A healthy ecosystem needs competition from rivals.
Finally, as a pope market trader myself, there’s value in having skin in the game. I learned more about papal politics, conclave procedure, and Catholic Church power dynamics in two weeks of trading than I ever would have from passively watching the news. I imagine the same is true for other traders, and other markets covering impactful, sometimes controversial, real-world events have a similar effect.
And in that sense, even a market that “misses” can be informative.
