Reportedly, well-respected stock trading company Knight Capital Group, accidentally released test software used to "verify that their new market making software functioned properly, into NYSE's live system".
From the article in The New York Times, explaining the events:
The problem on Wednesday led the firm's computers to rapidly buy and sell millions of shares in over a hundred stocks for about 45 minutes after the markets opened. Those trades pushed the value of many stocks up, and the company's losses appear to have occurred when it had to sell the overvalued shares back into the market at a lower price.
The company said the problems happened because of new trading software that had been installed. The event was the latest to draw attention to the potentially destabilizing effect of the computerized trading that has increasingly dominated the nation's stock markets.
Until this week, Knight had been one of the biggest beneficiaries of the evolution of the market, helping clients trade in and out of stocks at high speeds. The firm was responsible for 11 percent of all trading in American stocks between January and May, according to Adam Sussman at the data company Tabb Group.
|Did Google Earth find Atlantis?|
|Microsoft Vista Tiny|
|It's a Windows World|
|The Leopard is out|
|Dumpster Drive: Recycling Computer Files|
|Japanese Create Ice Cream That Does Not Melt|
|Amateur-Built Electric Car Going After Record Set by Tesla|
|“Banning polluting cars in 2040 or 2050 doesn’t actually look like a very bold move.”|
|Making a Movie Inside a Video Game|
|“This conversation about how technology is hijacking people is really catching on.”|
|Google Map Shows You the Most Photographed Areas of the World|
|“Our Internet handlers, not government, are using operant conditioning to modify our behaviour today.”|
|“Human and animal cells can be 3D printed into high-resolution tissue.”|
|“Nobody is forcing the participants to stay, of course, but if they leave, they won’t be paid.”|
|“That science fiction future where robots can do what people and animals do may be closer than you think.”|
|“The shift from fuel and pistons to batteries and electric motors is unlikely to take that long.”|
|“During this phase of decline, the US was likely to go through a phase of reactionary 'fascism'.”|