Flash crash

US banking giant Citigroup has said that one of its traders made an error in the so-called stock market "flash crash" in Europe on Monday.

A flash crash is an extremely fast fall in the price of one or more assets, often caused by a trading mistake.

Trading was briefly halted in several markets after major share indexes plunged just before 8am GMT on Monday.

Nordic stocks were hit the hardest, while other European indexes also plummeted for a short time.

"This morning one of our traders made an error when inputting a transaction. Within minutes, we identified the error and corrected it," the New York-based bank said in a statement late on Monday.

The flash crash caused European shares to fall suddenly on a day when trading was particularly thin due to public holidays around the world.

Sweden's benchmark Stockholm OMX 30 share index was one of the hardest hit, falling by 8% at one point, before recovering most of those losses to end the day 1.87% lower.

Flash crashes can be caused by human error, or so-called "fat finger" trades - a reference to someone incorrectly typing the details of a trade.

Such trading errors and the flash crashes they can cause are often costly. They have triggered shake ups of stock market rules and have even led to criminal convictions.

www.bbc.com/news/business-61303217