For about two hours on Monday morning, trading of about 40 stocks on the New York Stock Exchange was suspended after a technical glitch caused misquoted prices, including those of Berkshire Hathaway, which showed a drop of more than 99 percent.
The bug has been fixed, the exchange later said, adding that any trades made before the suspension would be reviewed. It is common for exchanges to reverse trades made when prices are clearly incorrect.
The outlandish numbers appeared shortly after the opening bell, around 9:45, when Berkshire Hathaway’s Class A shares were priced at just $185.10, a drop of 99.97 percent from $626,000. reached at the end of Friday’s negotiations. Trading at Berkshire Hathaway stopped immediately.
Less than two hours later, the suspension was lifted and Berkshire shares ended the day at $631,110, up 0.6 percent. (Berkshire’s Class B shares, like the vast majority of traded issues, were not affected by the issue.)
In a statement, a spokeswoman for the New York Stock Exchange said the malfunction had been caused by “a technical problem” with a data source that displays bids and prices, known as a securities information processor.
The Securities and Exchange Commission requires all exchanges to submit changes to their best bids and offers to the feed, which is operated by a branch of the stock exchange.
Other stocks affected by the issue included Chipotle, GameStop and movie theater chain AMC. Among the companies whose stock prices temporarily fell by almost 100 percent were Barrick Gold, the Bank of Montreal and NuScale Power, a developer of small nuclear reactors.
Overall, the S&P 500 rose slightly on Monday and trading in other parts of the market did not appear to be affected by the issue.
Trading failures like Monday’s are rare, but they do happen. In 2023, a bug caused wild price swings that affected more than 250 stocks. The declines that day were less extreme, and shares of big companies like Verizon swung between gains and losses before orders resumed.
Exchanges use built-in “circuit breakers” to automatically pause trading when a stock’s price suddenly swings widely. Exchanges also have rules that allow traders to flag erroneous trades and seek compensation if necessary.