The British trader accused of contributing to May 2010's "flash crash" is due to appear in court tomorrow where he faces extradition to the US.
US authorities have alleged that Navinder Singh Sarao, who has been nicknamed the "hound of Hounslow", rigged the market by using an automated process to place a large number of sell orders before withdrawing them shortly afterwards so he could take advantage of the artificially lowered prices.
They have accused the 37-year-old trader, who was arrested in April last year, of benefiting from his activities to the tune of $40m (£27.5m).
In particular, the authorities allege that Sarao's actions contributed to the Dow Jones Industrial Average suddenly dropping several hundred points in less than five minutes on 6 May 2010, although the market recovered later on in the day.
If Sarao is extradited to the US, he will face multiple commodities fraud and manipulation charges, which in total carry a maximum sentence of 380 years.