NYSE Arca Proposes Trading-Halt Rule Change for Corporate Actions Ahead of 23/5 Trading

NYSE Arca proposed a rule change to set specific steps for halting and resuming trading in a stock that faces a major corporate action.

NYSE Arca stated that the change supports its move to trade 23 hours a day, five days a week (see prior coverage). Under this new schedule, the exchange will only be closed for one hour overnight (from 8:00 p.m. to 9:00 p.m. Eastern time). NYSE Arca stated that firms historically used the long overnight break to prepare their systems for corporate actions and argued that a one-hour window is too short and could cause wrong prices and errors. To prevent the errors, under the new rule, NYSE Arca will pause trading in an affected stock before 9:00 p.m. ET the night before a corporate action takes effect and trading will resume the next morning at 8:00 a.m. through a "trading-halt auction." It said that gives the market an extra hour of price discovery before the 9:30 a.m. open.

The halt will apply to nine types of corporate events: trading-symbol changes; CUSIP number changes; dividends of at least 25 percent of the official closing price; forward and reverse stock splits; de-SPAC transactions; spin-offs; security-type changes, such as converting an ADR to ordinary shares; mergers or mandatory exchanges; and other events where the exchange decides a halt is needed to protect investors.

NYSE Arca said it understands that the other primary listing exchanges plan to adopt substantially identical rules so corporate actions are treated the same across the market.

The SEC is taking comments through August 3, 2026.