New York Stock Exchange says a bad software upgrade caused Wednesday’s

“I can’t say with precision exactly what drove it”, he said.

Yet screens used by investors everywhere continued to flash new trade prices in red and green for ExxonMobil, JPMorgan Chase and other NYSE blue chip stocks, as fresh transactions were executed on other platforms, including the Nasdaq, the NYSE’s cross-town rival. NYSE believes the glitch was caused by a problem with a software update it rolled out on Tuesday evening, the exchange said in a new statement released on Thursday.

The issue was investigated shortly after 11 a.m. and within 30 minutes, the exchange took the decision to suspend trading.

But USA officials are denying that the outages are related and that they were caused by hacking, according to multiple reports.

“But based on a hack of the New York Stock Exchange we would still be trading”.

The White House said US President Barack Obama had been briefed on the matter.

Officials at the exchange say there is no evidence of a cyber-attack, although the FBI said it is “monitoring the situation”.

In May 2012, a surge of order cancellations muddled the procedure of matching buy and sell interest in the Facebook Inc. As CNBC has reported, “trading essentially went on unabated”.

Homeland Secretary Jeh Johnson said he had spoken to United CEO Jeff Smisek. United Airlines grounded dozens of flights and delayed hundreds because of a systems issue.

Wall Street cheered a huge rebound in China, which is scrambling to put a bottom under its crashing stock market.

The outage came at a time when traders had plenty of other things to worry about. Dow member Microsoft slipped 0.1 percent following news it will cut 7,800 jobs as it moves to reorganize its struggling phone business.

Wednesday’s halt re-hatches the long debate on electronic trading. The exchange tinkered with the setup, but further trouble ensued, leading to a full halt of trading at 11:32 a.m. that lasted more than three hours. The Dow opened more than 240 points higher before giving back some of the gains.

Two months later, a highly anticipated IPO of Facebook on the Nasdaq exchange was marred by a series of technical problems, rattling investors unsure if their orders went through. In 2013, trading in options in Chicago was halted due to an outage caused by software problems.

So it’s kind of sad to admit it, but if the New York Stock Exchange closed, we wouldn’t really miss it.