outage

The complexity of U.S. stock-market structure is the “biggest obstacle” to ensuring systems run without failing, Nasdaq OMX Group Inc. Chief Financial Officer Lee Shavel said today.
The SEC chairman said she would push for new rules after a system caused a three-hour halt on the Nasdaq today.
CBOE said preliminary work in preparation for reconfiguring its computer systems caused the three-and-a-half-hour shutdown on April 25.