On Wednesday, a series of trading glitches on the New York Stock Exchange spiked volume to unusually high levels, and led to numerous trading halts just after the opening bell.

The issues arose from a routing error by Knight Capital, one of the industry’s biggest market-makers, ultimately affecting roughly 150 stocks.

The New York Stock Exchange later announced that it would cancel trades in six stocks affected, including: Wizzard Software, Quicksilver , E House , American Reprographics and China Cord Blood .

The incident was another mark against the industry, at a time when investor confidence is running low. Knight blamed technology and has not yet disclosed the financial impact from the trading, but traders expect it to take a more than $100 million hit.

The technical snafu at Knight is also the latest in a series of high-profile trading issues that have hit markets .

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