The New York Stock Exchange says it has resolved a technical glitch that helped cause trading halts in shares of dozens of companies on Monday morning, including Berkshire Hathaway Class A shares. The exchange said the technical issue had been resolved, and all impacted stocks resumed trading at 11:40 a.m. Eastern Time.
The glitch impacted trading in up to 49 stocks on Monday, according to the Consolidated Tape Association. In addition to Berkshire Hathaway Class A shares, stocks whose trading might have been impacted by the glitch included GameStop, Abbott Laboratories, AMC Entertainment Holdings, and Chipotle Mexican Grill, among others.
The NYSE on Monday afternoon said it was investigating what trading halts were caused by the technical issues and which were legitimate. Halts caused by the glitch “will be considered for potential busts,” the NYSE said.
The root cause of the halt in shares was caused by a code upgrade implemented over the weekend by the Consolidated Tape Association Security Information Processor, according to a person familiar with the matter. That system is used to consolidate stock data across major exchanges.
Before Monday, the opening reference price for stocks on listing markets handled by the CTA SIP was calculated by the SIP itself and the upgrade made it so the price would be calculated by the primary listing market of the stocks, the person said. It’s unclear why exactly the glitch only happened on certain securities, but the CTA SIP on Monday rolled back its code to the previous version, resolving the issue, the person said.
Class A shares of Berkshire Hathaway (BRK) stock were halted by the NYSE after prices showed a drop of more than 99%. Trading was halted as of about 9:50 a.m. on Monday at a price of $185.10, down 99.97% for the day. Berkshire Class B shares had fallen 0.97% to $410.36 and continued trading.
Shares of Barrick Gold showed a drop of more than 98% to $0.25 and were halted at about 9:56 a.m., while shares of NuScale Power showed a drop of a similar amount to $0.13.
Class A shares of Berkshire reopened just after 11:30 a.m., showing a price of about $640,000, up 2%. Trading in shares of Barrick and NuScale also reopened, with the gold miner rising about 1.7% to $17.38 and NuScale 3.8% to $8.40.
Earlier Monday morning, the NYSE, which is owned by Intercontinental Exchange, had said it was investigating an issue regarding Limit Up-Limit Down bands. Such limits are intended to prevent extreme price swings in stocks by stopping trades that take place outside of certain price bands.
The issue, which impacted more than an hour of trading on Monday, is the latest technical glitch to cause false prices to be published or huge swings in market prices over the past couple of decades.
In 2015, an outage caused trading to halt at the NYSE for nearly four hours. In 2013, trading was halted for three hours on the Nasdaq after problems connecting to the information feed used to distribute stock quotes. In the 2010 “flash crash,” major exchanges collapsed and rebounded, which market regulators attributed to automated trading after a trader sold a large number of S&P 500 futures contracts.
