The Nasdaq Composite Index was frozen for nearly an hour Tuesday due to a technical problem but shares traded normally, the operator of the Nasdaq Stock Market said. The index was frozen at 3,940.23 for about 50 minutes starting at 1555 GMT, according to a graphic on the website of Nasdaq OMX. The index began giving normal readings of stocks trade at 1645 GMT. Individual stocks that trade on Nasdaq, such as Apple and Facebook, continued to trade during the disruption. Nasdaq did not immediately respond to a query. A Nasdaq notice said the disruption halted trading of three different kinds of options because the overall index was not being disseminated. The glitch is the latest technical problem to befall the leading US exchange for technology companies following an August outage that halted trading for more than three hours. Michael James, managing director of equity trading at Wedbush Securities, said the glitch is \"definitely problematic.\" \"It does not do anything positive in terms of investor confidence in the vehicles we use every day to trade,\" James said. At 1735 GMT, the Nasdaq was up 5.70 points (0.14 percent) at 3,945.83.