NATCHEZ — Key Smith spent part of his morning Wednesday working to calm the nerves of some of his customers, who called with concerns about the unexpected shut down of the New York Stock Exchange.

Trading was suspended on the NYSE at about 10:32 a.m. by an unexplained technical glitch.

In an apparent coincidence, United Airlines grounded all of its flights on Wednesday, also because of a computer issue.

Smith, a partner with Natchez Wealth Management, said the NYSE shut down was caused by a software update.

“It was an internal thing. They verified there were no cyber attacks,” he said. “Every indication is that shutdown at the New York Stock Exchange and United Airlines were unrelated.”

Trading resumed on the NYSE at about 2:10 p.m.

Some open orders on the NYSE were cancelled, which potentially could have cost some investors money. Other stock exchanges were unaffected, Smith said, which means trading continued.

“The New York Stock Exchange is one of many exchanges and the others were trading regularly,” he said. “There are other routes to make trades, and they all worked properly.”