Polymarket Accuses Rival Kalshi of Corporate Spying, Idea Theft

Kalshi one of the biggest companies within Prediction market betting

Polymarket has accused rival prediction market platform Kalshi of corporate espionage and systematically copying its business strategies, according to an original report in the New York Times. The company has compiled a working dossier dubbed “copycat” that details roughly a dozen eyebrow-raising incidents and data points. According to the documents, Polymarket alleges Kalshi obtained confidential information about product launches and marketing campaigns, including a February grocery store promotion where Kalshi launched a nearly identical event just nine days before Polymarket’s planned debut. The allegations extend beyond idea theft to potential physical spying, with Polymarket reportedly tinting office windows due to concerns about surveillance. Both Kalshi and its investor Paradigm have denied all espionage claims as the competitive tensions between the two prediction market giants escalate.

Polymarket Builds ‘Copycat’ Dossier Against Kalshi Polymarket

The dossier compiled by Polymarket features roughly a dozen side-by-side screenshots documenting what the company views as suspicious patterns in Kalshi’s product launches and marketing campaigns. CEO Shayne Coplan publicly stated during a CNBC appearance that “Polymarket is Polymarket. And they’re a Polymarket copycat”.

The perpetual futures incident stands as a focal point in the allegations. Polymarket’s internal team had been developing perpetual futures contracts since January, setting April 21 as the announcement date. An hour before Polymarket’s scheduled announcement, The Information published an article revealing Kalshi’s plans to offer the same product. Polymarket executives viewed the timing as suspicious, with one insider stating, “They seemed to know we were going to announce that day”.

Another example involves social media posts from June 10, 2025. Polymarket announced a crypto price betting tool at 9:01 AM, garnering nearly 24 million views. Kalshi and Webull released a press release for a similar partnership product timestamped at 9 AM the same day. The dossier highlights this with the caption “SAME DAY?”.

Mobile advertising patterns also raised concerns. Polymarket began running Meta ads targeting California users with “Hey California” branding on Friday, August 22. By Monday, Kalshi had launched nearly identical ads with the same banner.

Physical Spying Concerns: The Paradigm Office Connection

Beyond digital concerns, Polymarket employees raised alarm about potential physical surveillance. Paradigm, the venture capital firm backing Kalshi, maintains offices in Soho directly across the street from Polymarket’s lower Manhattan location. The geographic proximity sparked internal discussions about whether competitor intelligence gathering extended beyond digital methods.

Paradigm’s offices feature floor-to-ceiling windows that provide direct sightlines into portions of Polymarket’s workspace. Several employees noted the windows potentially allow observation of computer screens from across the street. The venture capital firm has positioned itself as a prominent Kalshi backer, with cofounder and managing partner Matt Huang serving on the startup’s board of directors.

In recent months, Polymarket employees convened internal meetings to assess the surveillance risk. “We got together and discussed, like, ‘Is this possible?'” one insider stated, referring to concerns about office spying. The group reached a consensus based on their perception of Kalshi’s conduct: “With Kalshi, it is”.

Polymarket responded by installing tinted film on office windows during spring 2026. The privacy measure addressed employee concerns about visible workspace activity. An internal employee confirmed surveillance discussions occurred during company meetings, concluding such monitoring remained “entirely plausible” given past conduct patterns.

Kalshi and Paradigm Deny All Espionage Allegations

Kalshi spokesperson Jack Such rejected the espionage accusations outright. “This is sad and borderline delusional,” Such told The Post. “Polymarket is welcome to waste its time investigating. While they do that, we’ll keep building”.

In response to questions about alleged spying, a Paradigm spokesperson dismissed the claims as “laughable”. The venture capital firm’s representative offered no further elaboration on the surveillance concerns raised by Polymarket employees.

Such provided specific explanations for the timing coincidences cited in the dossier. He stated Kalshi had been working on its launch since 2024. For this reason, he believes The Information caught wind of Kalshi’s plans from a social media teaser posted on X on April 13. That post shows a video of what appears to be an infinite Slinky with the caption “Timeless,” a finance reference to perpetual futures contracts which never expire.

Addressing the “Hey California” campaign similarity, Such argued that Polymarket has no copyright or trademark over the “extremely common” phrase. “Attributing this coincidence to corporate espionage is delusional,” he stated.

Sources inside Polymarket told news outlets that Kalshi moles could be planted inside the trading exchange’s New York office.