Trials

British trader charged in 'flash crash' pleads guilty

In this March 23, 2016 file photo, British futures trader Navinder Singh Sarao leaves after the ruling in his extradition hearing at Westminster Magistrates Court in London.

In this March 23, 2016 file photo, British futures trader Navinder Singh Sarao leaves after the ruling in his extradition hearing at Westminster Magistrates Court in London.  (AP Photo/Matt Dunham)

A British futures trader has pleaded guilty during his first U.S. court appearance since helping to trigger a 2010 "flash crash" from his parents' suburban London home that wiped billions of dollars off the value of U.S. stocks.

Navinder Singh Sarao stood in a Chicago courtroom Wednesday with his legs shackled as a judge asked if he understood the consequences of pleading guilty, including that he could face 30 years in prison. The 37-year-old answered quietly, "Yes, your honor."

High frequency traders such as Sarao use programs to buy and sell in milliseconds, scooping up quickly-accumulating profits. They were the focus of Michael Lewis' best-selling book "Flash Boys."

Sarao pleaded guilty to wire fraud and spoofing under a plea deal. If he cooperates, prosecutors would ask for a reduced sentence.