| NEW YORK
NEW YORK NYSE Arca said on Tuesday that all systems were functioning normally after a technical issue in the prior session prevented some symbols from completing a closing auction.
The exchange said late Monday that its trading platform experienced a technical issue which resulted in a number of symbols to fail to conduct a closing auction or transition from the regular trading session to the late trading session at 4 p.m. ET (1800 GMT).
NYSE Arca said in a letter to clients on Tuesday that 341 symbols did not successfully complete a closing auction and the issue was caused by a software update. The exchange said it has reverted back to the prior version of software.
"One could argue the role of NYSE official closing prices is one of the most important in the market," said Spencer Midlin, analyst at Aite Group in Boston.
"Millions of portfolios and retirement accounts depend on the closing prices of NYSE-listed stocks and ETFs."
The exchange said the underlying cause of the disruption was "identified and remediated."
(Additional reporting by Herb Lash and Trevor Hunnicutt; Editing by Nick Zieminski)