Polymarket Accuses Kalshi of Corporate Espionage

Tinted Windows and a Rival Across the Street

Polymarket has accused its main rival, Kalshi, of corporate espionage, alleging they copied its product launches and may be surveilling its Manhattan offices, per a New York Post report. Having compiled an internal dossier it calls “The Imitators,” logging roughly a dozen incidents it deems suspicious, it has opened an internal investigation and gone to the press.

“There have been a couple too many coincidences,” Polymarket head of marketing Matthew Modabber told the Post. “There is bad intention in how they copy us. They’re breathing down our neck.” Polymarket says it had set a free grocery pop-up in New York for February 12, only for Kalshi to stage a similar voucher-driven promotion about nine days earlier.

The perpetual-futures timing drew the sharpest suspicion. Polymarket planned to unveil its take on the product on April 21; roughly an hour before the announcement, tech outlet The Information reported Kalshi was preparing its own. “They seemed to know we were going to announce that day,” one insider said.

Paradigm, a venture firm that backs Kalshi, leases offices directly across from Polymarket’s SoHo headquarters, with sightlines into parts of the floor and potentially employees’ screens, sources told the Post. Polymarket tinted some windows this spring, and staff have privately raised the prospect of Kalshi “moles” inside the firm.

Both companies rejected the claims. “This is sad and borderline delusional,” Kalshi spokesperson Jack Such told the Post, adding Kalshi had built its perps product since 2024 and that The Information likely caught wind of it from an April 13 teaser on X. A Paradigm spokesperson called the surveillance concerns “laughable.” No public evidence of espionage has surfaced to date, and the allegations are unproven.

The feud reflects how high the stakes have grown as the two firms swallow the sector. Kalshi overtook Polymarket in April taker volume for the first time ($5.42 billion to $1.99 billion, per Dune Analytics) after the pair dominated a record $25.7 billion in March. Polymarket has run on-chain since 2020; Kalshi won CFTC approval in 2021 as the first federally regulated U.S. prediction exchange.

The rival companies have closely shadowed each other’s roadmaps across the years with overlapping products, promotions and legal fights – a resemblance Polymarket now frames as theft rather than coincidence.