The New York Stock Exchange on Wednesday said it identified the culprit behind the wild price swings and numerous trading halts that marked the start of the previous trading session.
The NYSE said an erroneous ‘Sell Short Restriction” led to the incident.
“On January 24, 2023, a Sell Short Restriction (SSR) state was erroneously triggered in a subset of NYSE listed symbols.” It said the SSR on 81 securities — including big names like McDonald’s Exxon Mobil and Walmart — will be deactivated before the NYSE opening on Wednesday.
The restriction stems form a relatively recent rule, from 2010, that’s called the alternative uptick rule, that says that stocks can’t be shorted if they have dropped 10% or more in one day.
Dozens of stocks were briefly halted after Tuesday’s opening bell for volatility. Several stocks showed large opening moves that triggered circuit breakers that automatically halt trade in individual stocks. Trading largely returned to normal by 10 a.m. ET, but the NYSE said Tuesday that trades in more than 250 securities would be busted as a result of the incident.
In a Tuesday afternoon statement, the NYSE said that due to a “system issue,” the NYSE didn’t conduct opening auctions in a number of listed securities. The opening auction occurs at 9:30 a.m. ET and produces the opening price for individual stocks.
“Such events are extremely rare, and we are thoroughly examining the day’s activity to assure the highest level of resilience in our systems. We ended the day with a normal market close and expect a regular open on Wednesday,” said Michael Blaugrund, NYSE chief operating officer, in a statement late Tuesday.
—Steve Goldstein contributed reporting to this article.