UK trader accused of 'flash crash' role opposes extradition to U.S.
The U.S. Justice Department said on Tuesday that it had criminally charged Sarao, 36, of London, with wire fraud, commodities fraud and manipulation.
Sarao, who was arrested by British police on Tuesday, appeared at Westminster Magistrates' Court.
(Reporting by Michael Holden, writing by Estelle Shirbon; editing by Stephen Addison)