The British futures trader accused by US authorities of contributing to the 2010 "flash crash" faces a 30-year jail term after pleading guilty to charges of wire fraud and spoofing in a US court.
Navinder Singh Sarao, who traded futures on the Chicago Mercantile Exchange from his parent's home in west London, was extradited to the US to face charges last month.
Sarao pleaded guilty to one count of wire fraud and one count of spoofing in relation to the crash, which saw the S&P 500 index plummet 600 points in minutes, sending shockwaves through the global financial system.
Sarao used an automated trading program to manipulate the market for E-Mini S&P 500 futures contracts on the CME. This manipulation earned him significant profits and contributed to a major drop in the US stock market on 6 May, 2010.
During the extradition hearings in the UK, courts heard that the trader had funds of more than £30 million, including £25.5 million held in Switzerland.
Under a plea deal agreed with US prosecutors, Sarao will repay the US government $12.8 million. He has been released on bail pending sentencing.