In the largest ever such scheme, the group allegedly hacked into firms to read yet-to-be published information, then traded on it.
US prosecutors say they have broken up an international insider trading ring of hackers and securities traders that made tens of millions of dollars.
Nine people were charged in Brooklyn, New York and Newark, including Ukrainian hackers and security traders, accused of making $30m (£19m).
They are accused of breaking into the computers of companies that put out corporate press releases, and trading on the information before it was made public.
Five defendants were taken in custody, while arrest warrants were issued for four others in Ukraine.
The suspects were charged with 23 counts, including securities fraud, computer fraud and conspiracy to commit money laundering.
The US Securities and Exchange Commission brought related civil charges against the nine plus 23 other individuals and companies, bringing the total to 32. It said that overall the crime resulted in more than $100m (£64m) of illegal profit.
Federal authorities said it was the largest scheme of its kind ever prosecuted.
“This is the story of a traditional securities fraud scheme with a twist – one that employed a contemporary approach to a conventional crime,” said Diego Rodriguez, head of the FBI’s New York office.
The US Justice Department said in a statement that the scheme aimed to “hack into three business newswires and steal yet-to-be published press releases containing non-public financial information that was then used to make trades.”
Prosecutors said that starting in 2010, the hackers gained early access to hundreds of news releases from services including Marketwired of Toronto, Canada, PR Newswire, based in New York, and San Francisco-based Business Wire.
The news releases contained earnings figures and other corporate information.
The traders then used the information to make trades before the releases came out, exploiting a time gap ranging from hours to three days, prosecutors said.