Two weeks ago, one of Wall Street’s largest market-making and trading firms, relying on a computerized trading program, shook investors’ confidence in the market. Trying to gain an edge on its competitors, seventeen-year-old Knight Capital Group rushed out new trading software that wasn’t ready. Instead of fulfilling customer orders, the software unintentionally generated millions of erroneous trades, causing sudden wild price swings in dozens of stocks. As trading volumes expanded, some Wall Street participants profited from the unusually dramatic price swings triggered by the faulty software. Many retail customers, having no idea what was going on, wound up losing money. Some journalists accused Wall Street insiders of using their trading tactics to rip off small investors: but the opposite, in this case, seems more accurate. The mishap cost Knight $440 million in trading losses and forced them to accept a lifeline to skirt collapse.