The NYSE says a trading problem that halted dozens of stocks has been resolved

Trading in dozens of stocks on the New York Stock Exchange was briefly halted shortly after the market opened on Tuesday due to an apparent technical problem.

Big names affected included Morgan Stanley, Verizon, AT&T, Nike and McDonald’s, according to the NYSE. site. Many stocks have been shown to experience abnormally large moves at the market open, which could cause a volatility stop.

CNBC’s Bob Pisani said on “Sound on the street” that the problem seems to be technical and not something that happened on the trading floor.

Many of the affected companies resumed trading by 9:45 a.m. ET. The NYSE said at about 9:50 a.m. that all of its systems were operational.

The exchange said in a statement that it is still investigating the issue with the opening of the auction.

“In a subset of symbols, the opening of auctions did not take place. The exchange is working on clarifying the list of symbols,” the message says.

The NYSE, like some other exchanges, has automatic stops for stocks that move sharply in one direction or another. On a normal trading day, some stocks are halted due to volatility on the NYSE.

The other major US stock exchange, Nasdaq, appears to have been unaffected by the technical issue.

Correction: The NYSE experienced a technical issue on Tuesday. The previous version had the wrong day of the week.