A Machiavellian mastermind or a naïve kid? The story of the Flash Crash Trader On a cold morning in April 2015, half a dozen FBI agents and police officers pulled up outside a modest semi-detached house in Hounslow to arrest a man they considered to be among the most prolific and dangerous market manipulators in the world. Their target, Navinder Singh Sarao, had accumulated $70m buying and selling futures [...]