(MoneyWatch) -- Nasdaq said it has halted all trading in stocks listed on its exchange because of a technical problem, the latest in a long line of glitches that have disrupted financial markets.
The Nasdaq, heavily concentrated with technology stocks, is home to stocks such as Apple, Microsoft, Ebay, Yahoo and more recently Facebook.
The Securities and Exchange Commission said it is monitoring the situation.
The shutdown began at about 12:15 p.m. ET. As of 1:23 p.m. ET, the Nasdaq composite stood, unmoving, at 3,631, a gain of 31 points, or nearly 1 percent.
Earlier in the week, a major technological glitch shut down all trading in stock options, which give the owner a right to buy or sell a block of securities at a particular price, and are frequently used as insurance by investors.
Despite the uncertainty, the broader S&P 500 index was up 11 points and the Dow industrials were up 48 points.