It's probably not uncommon for City traders to wonder how they burnt so much cash during a drunken night on the town.
But Steve Perkins was left with a bigger black hole in his memory than most when his employer rang one morning to ask what he'd done with $520m of the oil trading firm's money.
It was 7.45am on June 30 last year when the senior, longstanding broker for PVM Oil Futures was contacted by an admin clerk querying why he'd bought 7m barrels of crude in the middle of the night.
The 34-year old broker at first claimed he had spent the night trading alongside a client. But the story began to fall apart when he refused to put the customer in touch with his desk for official approval of the trades.
By 10am it emerged that Mr Perkins had single-handedly moved the global price of oil to an eight-month high during a "drunken blackout". Prices leapt by more than $1.50 a barrel in under half an hour at around 2am – the kind of sharp swing caused by events of geo-political significance. Ten times the usual volume of futures contracts changed hands in just one hour.