By now, many players on trading floors have gotten used to the disruptions that can come from the highly automated new world of high-frequency trading.

But that doesn't mean they like it.

"This algorithmic trading is kind of out of control," Phil Silverman, managing partner at Kingsview Capital, said as officials at the New York Stock Exchange tried to make sense of what happened. "It seriously hurts investor confidence."

By mid-afternoon, no one still quite knew exactly why about 150 stocks experienced a blinding surge in market volume, causing momentary disruptions in the prices of nine Dow components and a slew of others across various categories.

The NYSE said in the afternoon that it would cancel tradesin six different stocks affected by the glitch, including Wizzard Software, China Cord Blood, E-House Holdings, American Reprographicsand QuicksilverResources. Trades executed at 30 percent higher or lower than the opening price will be canceled, the NYSE said.

Nearly 40 issues spiked more than 10 percent between the lows and highs, although prices of most of these issues stabilized in afternoon trading. Following are the 10 issues that gyrated the most in terms of percentage change between the day's low and the day's high price — Wizzard Software, China Cord Blood, E House, American Reprographics, Rare Element, Navidea Biopharm, Almaden Minerals, Quicksilver, Radioshack and Nordic American Tanker. Some of these shares trade on NYSE MKT, formerly NYSE Amex.

Authorities involved in reviewing the matter said Knight Capital, a trading outfit that employs algorithms used in high-frequency trading, said it experienced "technology issues" with its market-making procedures.