WSJ Reports Polymarket Faced $10 Million Stolen-Card Fraud Attempt

Polymarket US reportedly faced an attempted fraud operation involving at least $10 million in transactions tied to stolen debit cards in February, according to The Wall Street Journal. The incident involved fraudsters linking stolen cards to accounts on the prediction-market platform before attempting to move funds through wagers and withdrawals.

According to data reported by the Journal and shared by Wu Blockchain, Polymarket’s payment processor at one point rejected more than 80% of the deposits it handled as fraudulent. The reported rate was substantially above the industry norm of roughly 1%.

Stolen Cards Used in Polymarket Accounts

The fraud attempt centered on Polymarket US accounts connected to stolen debit cards, with the perpetrators seeking to move at least $10 million through the platform, the Journal reported.

The episode highlights the scale of suspicious payment activity identified by Polymarket’s payment-processing systems. The more than 80% rejection rate cited by the Journal refers to deposits flagged as fraudulent by the payment processor during the period described in the report.

The reported activity involved both wagers and withdrawals, according to the account of events. The Wall Street Journal based its reporting on people familiar with the matter.

CEO Shayne Coplan Reportedly Told Staff to Keep Growing

The Journal also reported that Polymarket employees raised concerns internally about the fraud-related activity. According to people familiar with the events, CEO Shayne Coplan responded by telling staff to continue growing the business and pay a fine if regulators eventually discovered the issues.

The reported comments came amid markets concerns over the platform's handling of suspicious transactions and regulatory exposure. The account represents the characterization of people familiar with the events and should not be treated as an established finding by regulators or a court.

Polymarket disputed the implication that it lacked controls for suspicious activity. The company said it has procedures designed to detect and respond to potentially suspicious transactions and remains committed to cooperating with regulators and law enforcement.

Polymarket Faces Continued Regulatory Scrutiny

The reported fraud incident comes as Polymarket faces broader scrutiny over its compliance and operations in the United States. The company has previously been subject to regulatory action, including a 2022 settlement with the Commodity Futures Trading Commission involving its operation of event contracts.

More recently, regulators and lawmakers have continued examining prediction-market platforms and their safeguards. The House Oversight Committee in May 2026 requested documents from Coplan concerning Polymarket's identity-verification policies, among other issues.

Separately, Polymarket has said it is strengthening its ability to detect misconduct, including through blockchain analytics, machine learning and trade-surveillance tools. Reuters reported in August that the company had also established a new investigations and intelligence function ahead of the U.S. midterm elections.

The Wall Street Journal's latest report places the February stolen-card incident within that broader compliance history, while Polymarket maintains that it has procedures for identifying suspicious activity and works with authorities.

Writer: Victoria Hale
Technology & Blockchain Writer

Victoria Hale writes about blockchain technology, digital infrastructure, and the intersection of emerging technologies with finance. Her articles explore how new protocols and systems are shaping the evolving digital economy.

She prioritises clarity and accuracy when explaining technical developments to a general audience.