On August 1, 2012, a deployment failure in Knight Capital Group’s SMARS routing system triggered one of the most damaging software breakdowns in modern financial markets. A technician failed to copy new Retail Liquidity Program code to one of eight servers. That server still contained obsolete “Power Peg” code, and a repurposed flag activated it. Because the old function no longer correctly recorded completed orders, the system repeatedly generated new orders instead of stopping.
Over roughly 45 minutes, Knight’s algorithms produced about 4 million executions covering more than 397 million shares across 154 stocks, disrupting prices in 148 New York Stock Exchange-listed companies. Wizzard Software’s share price, for example, moved from $3.50 to $14.76. Knight recorded a pre-tax loss of approximately $440 million, while contemporary accounts described the overall trading error as costing about $460 million. Its stock fell more than 70 percent, and the company raised roughly $400 million on August 5 in emergency convertible financing led by Jefferies. Knight agreed to be acquired by Getco in December 2012; the merger closed in July 2013, creating KCG Holdings. The source also records earlier settlements, including $79 million paid to customers in 2004 for overcharging, but does not identify a criminal finding arising from the 2012 software failure.