The critical data processing system responsible for a three hour trading halt on the Nasdaq stock exchange was running on an outdated version of Windows operating system, it has been claimed.
According to a report by the Wall Street Journal, Nasdaq is continuing to run its securities information processor (SIP) - used by exchanges to consolidate quote and trade data before being sent out publicly - on Microsoft's Windows Server 2003 operating system.
Problems with Nasdaq's SIP were the cause of a major outage on the exchange in August, with securities trading halted for three hours. The problems were caused by the SIP failing to switch to backup systems following an 'unprecedented' influx of data from rival exchange NYSE.
Sources told WSJ that the Windows operating system is not thought to be the root cause of the systems failure, but its use served to highlight the underinvestment in trading systems in recent years.
Exchanges' technology platforms have came under increased scrutiny following Nasdaq's outage, with Securities and Exchange Commission (SEC) subsequently demanded that exchanges review safeguards and processes to help avoid further disruption after a number of high profile incidents.
It is not the first time that Nasdaq has received criticism for its use of outdated operating systems. In 2011 an FBI investigation into a security breach reportedly revealed that the exchange was an "easy target" as servers were still running on Windows 2003, and had not had security patches installed.
In separate news, it was reported by Reuters that a US judge has denied Nasdaq's request to reject lawsuits from investors claiming to have lost money following problems during Facebook's IPO in 2012. US District Judge Robert Sweet however noted that Nasdaq had failed to put in place adequate "stress tests" prior to Facebook's floatation.