The rivalry between Polymarket and Kalshi reaches a new milestone in New York

Polymarket claims that its rival Kalshi copied a dozen of its product launches, and even suspects physical surveillance of its New York offices. The company compiled an internal file, tinted its windows, and took the matter to the press. The predictive markets sector has never been so fiercely contested.

Imitations too timely to be accidental

Polymarket cites several timing coincidences that raised suspicions. On February 12, the platform organized a free food distribution in New York; Kalshi had launched a similar operation with discount vouchers nine days earlier.

Same scenario with perpetual futures contracts: Polymarket planned an announcement on April 21, and an hour before, The Information revealed that Kalshi was preparing exactly the same thing.

“There were a few too many coincidences,” said Matthew Modabber, Polymarket’s marketing director, to the New York Post. “Their imitations are malicious.“

The geographic context adds another layer of suspicion. Paradigm, the venture capital fund backing Kalshi, rents offices opposite Polymarket’s headquarters in SoHo, with a partial view of the floor and, according to internal sources, some screens. 

In response, Polymarket tinted its windows this spring. Employees privately mentioned the possibility of “informants” from Kalshi within the company itself.

Kalshi disputes, but the market has already ruled

Neither Kalshi nor Paradigm are intimidated by these accusations. Jack Such, Kalshi’s spokesperson, called the matter “almost delirious,” explaining that the surveillance product in question had been in development since 2024 and that a teaser published on April 13 on X had probably informed The Information. 

A Paradigm spokesperson called the surveillance concerns “laughable.”

No public evidence of espionage exists to date.

What is documented, however, is the commercial power dynamic. In April 2026, Kalshi surpassed Polymarket in trading volume for the first time: $5.42 billion versus $1.99 billion, according to Dune Analytics. 

Yet the two platforms together dominated the market in March with a record volume of $25.7 billion. This rivalry also takes place in a tense regulatory context: Kalshi has already formally required Polymarket to strengthen its KYC controls, under threat of having to close its offshore platform, a pressure that has only worsened relations between the two players.

In short, this case illustrates the harshness of a maturing market. Record volumes, congressional investigation, product war: Polymarket and Kalshi compete for every share point. Espionage accusations, whether founded or not, reflect a real tension between two visions of the industry. For now, no proof has emerged, but the predictive markets sector likely has not finished fueling the story.