Sterling's algo-fed slump renews concerns over flash crashes
Computer-initiated “flash crashes” are causing jitters in forex markets, with the latest fall in the pound raising new fears. Early on Monday, Japan time, the pound reached $1.1980, its lowest level against the dollar since 7 October, when the currency lost 9% of its value in under a minute. The pound’s steep fall this time was precipitated by investors' concerns over a hard Brexit. However, the investors were not human: algorithmic trading systems had reacted to headlines containing the words "hard Brexit" and started selling heavily. With uncertainty about Brexit continuing, it is likely that the pound will remain hostage to flash crashes for some time.
TOKYO -- The specter of "flash crashes" triggered by computer-initiated selling is haunting the foreign exchange markets, with the latest plunge of the British pound adding to the anxiety.

Early on Monday, Japan time, the pound touched $1.1980, its lowest level against the greenback since Oct. 7. On that day in October, the currency dropped 9% in less than a minute.