a trader works on the floor of the new york stock exchange nyse president lynn martin and other exchange officials confirmed to cnbc that the root cause of the big boards trading glitch at the tuesday open was due to a manual error involving the exchanges disaster recovery configuration after the 911 disaster the nyse was obligated to maintain a primary trading site at the nyse and a backup site which is in chicago on monday evening routine maintenance was being performed on the software for the chicago backup site on tuesday morning the backup system chicago was mistakenly still running when the primary system nyse came online because the backup was still running when the primary site started up some stocks behaved as if trading had already started as a result designated market makers dmms who would normally publish an opening auction print for each stock were prevented from doing so because the system operated as if an opening had already occurred this caused significant price dislocations and trading halts martin said the nyse was looking into implementing stronger testing protocols