The SEC has approved the NYSE’s proposal to amend Section 202.06 of the Listed Company Manual to prohibit listed companies from issuing material news after the official closing time for the NYSE’s trading session until the earlier of:

• Publication of such company’s official closing price on the NYSE, or
• Five minutes after the NYSE’s official closing time

The approved rule includes an exception to permit compliance with Regulation FD, which requires a public company to publicly disclose material information following a non-intentional disclosure.

The rule specifies that the official closing time for the NYSE is typically 4 p.m. Eastern time, except for certain days when the official closing time is 1 p.m. Eastern time.

The change was made to reduce the likelihood of investor confusion that could result if material news is issued prior to the completion of the NYSE’s closing auction but while trading is continuing on other markets.

NYSE's memo states the rule change is effective immediately.