NASDAQ Trading Halted by Technical Issue

Technical trouble with a computer stock pricing system forced NASDAQ to shut down the high-tech heavy stock exchange shortly afternoon eastern time. Trading didn't resume until shortly before trading ended at 4 p.m.

The financial market grinds to a standstill as a "glitch" hits the major exchange.

New York's second largest financial exchange halted all trading on Thursday after a technical issue raised alarm bells about the integrity of the stock quote system. The NASDAQ Exchange halted trading at 12:20 p.m. EDT. A market summary note on posted at 12:35 p.m. EDT referred to the issue as an "apparent glitch."

That glitch is tied to the NASDAQ Unlisted Trading Privileges (UTP) Securities Information Processor (SIP) quote dissemination system.

"Due to an issue at the UTP SIP affecting quote dissemination, NASDAQ has implemented a regulatory halt for trading in all Tape C securities until further notice," a NASDAQ Market System Status stated.

NASDAQ's market system status first reported "momentary interruptions" at 11:45 a.m. EDT. At that time, the market said the interruptions lasted from approximately 10:57 to 11:03 a.m. EDT and were resolved with the system operating normally at 11:45 a.m. At 12:09 p.m., NASDAQ warned that it was experiencing quote submission issues with the UTP SIP.

As of 1:30 p.m. EDT, NASDAQ has not yet restarted the market. The exchanged did post a market system status note indicating that when it does reopen trading, there will be a five-minute quote-only period.

"Additionally, NASDAQ will clear all stale quotes from the UTP SIP prior to the commencement of trading," NASDAQ stated.

The outage at NASDAQ is perhaps the largest halt in trading at the exchange since 2001. At this time, it is not yet clear what caused the quote dissemination system glitch and whether or not human error or system-level malfunction is at the root cause.

As of 2:28 p.m. EDT, a market system status note indicated that NASDAQ is aiming to restart equity trading at 3:10 p.m. EDT.

Update: Trading remained closed until shortly before the end of the trading day at 4 p.m. But the market ended the day up 38.92 points.

Sean Michael Kerner is a senior editor at eWEEK and Follow him on Twitter @TechJournalist.

Sean Michael Kerner

Sean Michael Kerner

Sean Michael Kerner is an Internet consultant, strategist, and contributor to several leading IT business web sites.