Bank stocks among those that plunged 99% due to NYSE glitch

Multiple U.S. company stocks temporarily and erroneously dove by 99% or more on Monday morning due to a now-resolved technical issue with the system that disseminates real-time trade and quote information from the New York Stock Exchange.

BMO Bank, Berkshire Hathaway, Barrick Gold, NuScale Power and other companies' stocks saw trading halted after 9:40 a.m. Eastern time, each at slightly different times. In each case, within a couple of hours, trading on the stock resumed at prices within 10% of the previous day's close.

The stock exchange, which is owned by Intercontinental Exchange, said a technical issue with industrywide price bands published by the Consolidated Tape Association led to the halts. The association oversees the dissemination of real-time trade and quote information for NYSE and other regional stock exchanges. The association has had 100% system availability in 17 of the last 20 quarters, according to its website.

According to the association, the problem was related to limit up-limit down bands meant to prevent extreme price movements in individual stock by preventing trades above or below a set percentage of the average price of the stock in the preceding five minutes. The bands were developed as part of the response by financial regulators and exchanges to the flash crash of 2010, which temporarily wiped out nearly $1 trillion in market capitalization in a few minutes.

The stock exchange halted trading on more than 70 symbols on Monday citing limit up-limit down bands. Of those, 40 were related to the error, including Banco Santander-Chile and JPMorgan Core Plus Bond ETF.

Some stoppages appeared unrelated to the tape association's technical problems. GameStop, for example, saw vast stock price climbs after stock market influencer Roaring Kitty announced a large position in the stock. The company's stock has been the subject of many retail traders' fascination since January 2021.

Since the 2010 flash crash, other stock market glitches have seized all or parts of the system. In 2015, a four-hour halt across the stock exchange was caused by glitches that started with a software update. In 2013, a three-hour trading freeze seized Nasdaq-listed securities when the securities information processor — the same processor involved in Monday's technical issues — became overwhelmed by a sudden burst of quotes. And in 2012, Facebook's initial public offering overwhelmed the Nasdaq for more than two hours.