The story of what triggered almost $10m (€7m) of losses on the Brent oil market on Tuesday is still being pieced together, but one thing is clear: Steven Noel Perkins, the broker accused by bosses at PVM Oil Associates of "unauthorised trading", made his trade at a very unusual time.

Trading from his UK home at about 2am on Tuesday, it was the most illiquid time of day in the Brent futures market - a gap left between New York and Singapore hours, in which only a handful of Tokyo-based traders are active.