Quite surprising. The three-hour long outage at NASDAQ OMX Group, Inc. (NASDAQ:NDAQ) received harsh criticism from the industry, media, investment fraternity and regulators. But CEO Robert Greifeld said in an interview with CNBC that customers of the exchange have given him positive feedback for the way he handled the world’s longest trading disruption due to technical glitches.

NASDAQ

Nasdaq doesn’t identify outside part

Yesterday, the Mecca of tech stocks halted trading for more than three hours after technical problems prevented some investors from seeing stock quotes. Had the exchange allowed trading, certain traders would have received the same data, which many others couldn’t. That would have created “information asymmetry”, said Greifeld.

However, the exchange where tech giants like Apple Inc. (NASDAQ:AAPL), Google Inc (NASDAQ:GOOG), Facebook Inc (NASDAQ:FB) and Microsoft Corporation (NASDAQ:MSFT) are listed hasn’t given an official explanation of what caused Thursday’s outage. NASDAQ OMX Group, Inc. (NASDAQ:NDAQ) has failed twice since last year. The exchange was fined $10 million for technical glitches during Facebook Inc (NASDAQ:FB) IPO last year. Later, NASDAQ OMX Group, Inc. (NASDAQ:NDAQ) claimed that they have taken necessary measures to prevent such issues in the future. Everybody is wondering where those systems are.

John Waggoner of USA Today says that the finger-pointing and criticism will keep going on until the stock exchange comes up with an explanation. Greifeld blamed outside issues for the outage, without naming any institution or individual. When CNBC asked whether the outage was due to NYSE or Arca, he refused to identify the outside party.

Nasdaq to go on defensive driving

Greifeld emphasized that the stock exchange will focus more on ‘defensive driving.’ During and after the outage, the media and investment fraternity tried contacting Robert Greifeld, but he didn’t address the public. He said he was too busy trying to fix the problem to make public statements. So, how and who will update investors who risk losing money?

Thursday’s outage has opened the way for further criticism of electronic trading. Critics have already been arguing that the U.S. financial market is too fragmented. Experts told Bloomberg that the latest outage could embolden calls for a change in electronic trading.

NASDAQ OMX Group, Inc. (NASDAQ:NDAQ) shares were up 0.82% to $30.71 at 11:17 AM EDT.