The British financial trader dubbed the Hound of Hounslow has admitted helping trigger a multi-billion-dollar Wall Street crash from a suburban UK home.
Navinder Singh Sarao, 37, appeared in leg shackles when he pleaded guilty to charges linked to the 2010 financial meltdown in a Chicago court room on Wednesday.
Associated Press said the case judge told the Briton he faces up to 30 years in prison after admitting to wire fraud and spoofing under a plea bargain, over the crimes orchestrated from his parents' home 3,500 miles away in west London.
Sarao was sent to the US in October after losing a High Court challenge against a decision to extradite him over the "flash crash", which saw the Dow Jones Industrial Average plunge 600 points in five minutes, wiping tens of billions of pounds off the value of US shares.
US authorities claimed during court appearances in the UK that Sarao made 875,000 US dollars (about £716,000) on May 6 2010, the day of the crash, part of alleged illegal earnings of more than 40 million dollars (£26 million) over a five-year period.
He faced 22 charges, which carry sentences totalling a maximum of 380 years.
At an extradition hearing at Westminster Magistrates' Court in March, District Judge Quentin Purdy ruled that the Londoner, of Clairvale Road, Hounslow, could be sent to stand trial in the US.
Lawyers for the former bank worker and Brunel University student argued at the time that his actions did not constitute a crime.
Two judges at the High Court in London in October refused to give him permission to challenge the extradition order and he was later sent across the Atlantic.