Polymarket US Adds 15-Minute Bitcoin Bets as New York Sues

The round-the-clock contracts launched Sept. 22, two days before New York sued the platform. Researchers have flagged manipulation in shorter five-minute Bitcoin bets on Polymarket's offshore site.

Polymarket US Adds Bitcoin Bets That Settle Every 15 Minutes

Francis Gable

29/09/26 · 2 minSeptember 29, 2026 · 2 min read

Polymarket's U.S. app started selling Bitcoin contracts that settle every 15 minutes on Sept. 22. The rounds run around the clock, up to 96 a day.

The product moves a federally regulated app toward rapid, repeat play that looks more like a casino game than a forecast.

Two days after the launch, New York's attorney general sued the company behind Polymarket US, alleging it runs an unlicensed gambling business open to users aged 18 to 20.

How a 15-Minute Round Works

Each market asks one question. Will Bitcoin's price at the end of the quarter hour be at or above its price at the start? A winning share pays $1 and a losing share pays nothing. Traders can sell before the round closes.

Both prices come from CF Benchmarks' Bitcoin Real-Time Index, according to the market rules. Polymarket averages 60 index readings from the last minute before each time instead of using a single trade.

That design matters because of research on the company's offshore platform. A June 2026 paper found signs of settlement manipulation in five-minute Bitcoin contracts: bursts of spot trading just before settlement pushed the price, then reversed.

The authors said manipulators profited mostly at the expense of retail traders, and that the pattern was "largely absent" in 15-minute contracts.

New York's Lawsuit Leaves the Crypto Rounds Open

New York's lawsuit asks a court to shut Polymarket US out of the state until it holds a gambling license. It also seeks fines of three times its gains. Polymarket answered with its own suit in federal court, as FairGambling reported when New York filed its case.

The petition does not mention Bitcoin or the 15-minute product. Its examples focus on sports, politics and entertainment. Polymarket US says it operates as a federally regulated exchange, separate from the company's global site.

That global site still lists five-minute rounds on Bitcoin, Ethereum and other coins, the format the researchers flagged. Whether any New York court order would reach the Bitcoin rounds remains unresolved as the case moves forward.

Treat gambling as entertainment you pay for. 18+, and if it stops feeling like entertainment, help exists at BeGambleAware and GamCare.