The attackers apparently targeted the news organization, which owns The Wall Street Journal among other finance-focused publications, seeking potentially market-moving information before it was published. For example, reading an article about M&A negotiations before the rest of the world could enable a trader to buy a stock before its price surged—a significant (though illegal) advantage.

But it’s unclear whether the Russian group actually made any money off the theft: “The FBI and SEC have spent months trying to determine exactly how the hackers could profit from what they took,” according to the report, which cites unnamed sources.

And Dow Jones denied any knowledge of the attack (or the regulators’ investigation) implying in a statement that Bloomberg could have fabricated the news to make its rival media outlet look bad. “We are looking into whether there is any truth whatsoever to this report by a competitor news organization,” Dow Jones told Bloomberg.

The alleged breach is the latest example of a cyberattack seeking to obtain non-public information in order to gain a market advantage. In August, the SEC busted an insider trading ring that had made $100 million by working with hackers to get an early look at financial press releases, from which they gleaned illegal stock tips.