A blockchain-forensics firm has identified 19 connected accounts on the prediction-market platform Polymarket that placed near-perfect bets on the quarterly earnings of companies audited by KPMG, according to an analysis reported by The Wall Street Journal on Friday. The accounts won 41 of 42 bets tied to KPMG-audited firms — a 98% success rate — earning about $22,000 in total.

The bets covered 18 KPMG-audited companies, including Wells Fargo, Home Depot and DoorDash, and ran from November 2025 through several months afterward, according to Bubblemaps, a blockchain forensics firm that has previously probed other cases of suspicious activity on Polymarket. On bets placed against companies audited by other firms, the 19 accounts recorded an 82% win rate.

The accounts, which traded under names including “greatfan1983,” were linked through digital fund flows that traced a complex web of transactions between them, Bubblemaps said — a pattern the firm said suggests a single person or team was behind them, possibly trying to obscure their activity. Some of the 19 accounts also placed bets on sports, politics and other areas, but the vast majority of their profits came from the successful bets on KPMG-audited companies, according to the analysis.

“This is highly symptomatic of someone with an unfair information advantage,” said Nicolas Vaiman, co-founder and chief executive of Bubblemaps. The firm cautioned that its analysis is not proof of insider trading.

On March 18, General Mills reported disappointing quarterly earnings, driven in part by a decline in snack sales, and the company’s stock fell about 3% that day. The “greatfan1983” account, which mostly wagered on KPMG-audited companies, recorded a $654.40 gain on the General Mills miss. In two cases, the accounts placed offsetting wagers that netted them profits regardless of whether the company beat or missed estimates; Bubblemaps netted those two losses against the profits for its analysis.

A KPMG spokesman said the firm has “zero tolerance for violations of our well-understood and clear policies against trading on nonpublic client information, including on prediction markets.” The spokesman added that KPMG regularly updates training to reinforce those policies and has “enhanced our monitoring capabilities and continually explore emerging technology solutions to protect our capital markets from these dynamic threats.”

Concerns about a KPMG-linked trader surfaced publicly in December, when a Polymarket trader using the name “Extractive Manatee” raised the possibility on Discord, noting that a series of large bets on earnings of companies including CarMax, DoorDash and Home Depot shared a common auditor. “I am not one to scream insider and this is the first case in earning markets I actually think could be cheating,” Extractive Manatee wrote, urging Polymarket staff to investigate.

KPMG is one of the “Big Four” accounting firms and acts as the independent external auditor for dozens of S&P 500 member companies. The firm audits about 10% of companies registered with U.S. securities regulators, placing it fourth behind Deloitte, EY and PwC, according to Ideagen Audit Analytics. Auditors sign off on the financial data in companies’ annual reports and carry out less rigorous reviews of their quarterly earnings.

The analysis comes after The Wall Street Journal reported in August that federal authorities were preparing to bring charges against a KPMG employee over alleged insider trading on Polymarket, part of what the Journal described as a growing crackdown on wrongdoing in prediction markets. It could not be learned whether the operator of the 19 accounts is the employee under investigation.

As prediction markets have grown in popularity, they have drawn scrutiny over the potential for insider trading. U.S. and Israeli authorities have charged military personnel with using secret information to make money on Polymarket, while officials have accused other traders of using their knowledge of sensitive company data or even President Trump’s planned speeches to place profitable bets.

Charges in the KPMG employee case could come this fall, the Journal reported, citing people familiar with the investigation. The people cautioned that a final decision on bringing charges has not yet been made. Insider trading cases can be brought criminally or civilly. Federal authorities are also preparing charges against a U.S. servicemember suspected of placing Polymarket bets on military operations that earned more than $1 million, the Journal reported.

A Polymarket spokesman said: “While we do not comment on specific law enforcement matters, we regularly refer matters to law enforcement and support ongoing investigations as part of our commitment to protecting the integrity of our markets.” The Wall Street Journal noted that Polymarket has a data partnership with Dow Jones, the Journal’s publisher.

In 2014, a former KPMG partner in Southern California was sentenced to 14 months in prison for an insider-trading scheme in which he passed tips about the firm’s clients to a friend in exchange for cash and gifts including a Rolex watch.