Prediction markets rivalry turned into full spy thriller territory this week, with Polymarket quietly assembling a dossier on competitor Kalshi codenamed “copycat.”
According to a New York Post exclusive, the dossier catalogues roughly a dozen instances in which Polymarket believes Kalshi has stolen its ideas and front-run its product launches.
Insiders told the Post that the documented cases represent “only one tenth” of what Polymarket believes it has identified, suggesting the full list is extensive.
The suspicions range from near-identical social media advertisements to uncannily timed product announcements that appeared to mirror Polymarket’s own planned launches.
The breaking point came in February when Polymarket had spent months planning a pop-up grocery store event in lower Manhattan, a $643,000 production, only for Kalshi to launch its own free-grocery stunt in New York nine days earlier.
“Their intent was to just dilute our event,” a Polymarket source told the Post, capturing the frustration behind what had become a pattern of alleged imitation.
In April, Polymarket had set the 21st as the announcement date for a new perpetual futures trading product, but a tech publication revealed Kalshi’s near-identical product about an hour before the news was due to go live.
“They seemed to know we were going to announce that day,” said one insider, with theories ranging from internal moles to something considerably more cinematic involving office sightlines.
Paradigm, a venture capital firm backing Kalshi, rents office space in New York’s SoHo neighbourhood directly across the street from Polymarket’s offices, with a reported line of sight to employee screens, prompting Polymarket to tint its windows.
Kalshi dismissed the accusations as “sad and borderline delusional,” while Paradigm’s response was a single word: “Laughable.”
The drama is playing out as both companies sit on enormous valuations, with Polymarket targeting $15 billion and Kalshi recently valued at $22 billion, all while facing growing regulatory scrutiny.
Turning to the 2026 World Cup, the Financial Times explored how traditional sports betting operators are scrambling to hold ground as prediction markets encroach on their territory ahead of the tournament.
Flutter chief Peter Jackson called the 48-team, 104-match tournament spread across the US, Canada, and Mexico “the biggest betting opportunity we’ll have ever seen.”
DraftKings boss Jason Robins described it as “a huge focal point for customer acquisition,” though both executives are reportedly nervous about the rise of prediction market competitors.
For the first time, a major global football tournament is being staged in the shadow of Polymarket and Kalshi, which now derive most of their income from sports wagers and can operate in US states where traditional sports betting remains banned.
Trades on the World Cup winner have already totalled almost $1.5 billion on Polymarket alone, underlining just how rapidly the market has matured ahead of kick-off.
Flutter is responding with a gamified in-play interface for penalty kicks, expanded parlay promotions, and microbetting intervals borrowed from American football, while DraftKings has launched a Spanish-language product targeting an underserved football audience.
Entain’s Stella David flagged that the expanded format could produce “wildly fluctuating margins” given the volume of high-scoring blowouts expected from the tournament’s debutant nations.
Jackson admitted he is hoping for an England win, while acknowledging that such an outcome would deliver a serious financial hit to Flutter’s bottom line.
Finally, sport management professor David Bockino of Elon University and author of Over/Under: An Unexpected History of Sports Betting, pushed back on the familiar narrative that gambling corrupts American sport, arguing instead that gambling built it.
Baseball’s earliest fans showed up primarily to wager, and John Thorn, the official historian of Major League Baseball, called gambling a “vital spark” that transformed the sport from a local curiosity into a national pastime.
The NFL itself was literally founded by gamblers, with Giants owner Tim Mara a bookie and Steelers owner Art Rooney a prolific bettor, while the point spread reportedly kept viewers locked into the very first Super Bowl.
Bockino’s conclusion is that betting is too deeply wired into the fabric of American sport for any single scandal, however explosive, to unravel nearly two centuries of symbiosis between the two.

