A technical glitch on the stock market caused sharp swings in dozens of stocks early Wednesday, causing confusion and disarray in the first hour of trading.

It was the latest breakdown in the increasingly complicated electronic systems that run stock trading, which have been showing signs of strain as more traders and big investment firms use powerful computers to carry out trades in mere fractions of a second.

Coming less than three months after a snafu tarnished the debut of Facebook, the latest bug on Wall Street threatens to further erode investors' confidence in U.S. financial markets, experts say.