Sources: federal authorities prepare to charge a US serviceman and a KPMG employee with insider trading on prediction markets, as part of a new batch of cases (Dave Michaels/Wall Street Journal)

Federal investigators are preparing to indict a U.S. serviceman and a KPMG employee for allegedly using nonpublic information to trade on prediction markets, adding them to a recently disclosed series of insider-trading prosecutions. The charges stem from coordinated efforts to monitor illicit activity across multiple platforms.