A self-described day trader from Pennsylvania was indicted Wednesday (8 November) for running a "cyber boiler room" scheme to illegally trade through over 50 hacked online brokerage accounts. Joseph Willner, 42, of Ambler, Pennsylvania, was charged with securities fraud, conspiracies to commit securities fraud and computer intrusions, wire fraud and money laundering.

According to the indictment, Willner was accused of conspiring with others between September 2014 and May 2017 to hack into victims' online securities brokerage accounts and illegally use them to place unauthorised trades. In some cases, they also liquidated existing positions in the victims' accounts to fund the unauthorised trades as well.

As part of the scheme, Willner used brokerage accounts in his name to place "short sale" offers for companies' stock at artificially high prices. Meanwhile, his co-conspirators hacked into victims' online brokerage accounts and used them to buy the same companies' shares.

These shares would then be repurchased by Willner and his co-conspirators at market or below-market prices, allowing them to profit. Willner immediately profited off the fraudulent trades, which would usually take place within minutes, based on the difference between the artificially high short sale price and the lower price at which he repurchased the stock, authorities said.

He also laundered proceeds to at least one co-conspirator using bitcoin.

In a direct message on Twitter, one of the co-conspirators told Willner that "legal trading too hard". Willner replied that he would be a "good training partner".

Willner and his co-conspirators made at least $700,000 ($532,910) in profits through the hack-and-trade scheme which resulted in a loss of more than $2m (£1.5m) to affected brokerage firms.

"This case involves a 21st Century cyber boiler room, except the buyers were not even aware they were purchasing shares of stock," William Sweeney, assistant director-in-charge of the FBI, said in a statement. "The FBI will continue to investigate and bring to justice those who commit securities fraud in an effort to ensure the fairness and integrity of our financial markets."

Willner faces a maximum sentence of 20 years in prison if convicted. Last week, the US Securities and Exchange Commission filed civil charges against him as well.