Pursuant to Section 19(b)(1) ^[1] of the Securities Exchange Act of 1934 (the “Act”) ^[2] and Rule 19b-4 thereunder,^[3] notice is hereby given that, on November 2, 2026, the Investors Exchange LLC (“IEX” or the “Exchange”) filed with the Securities and Exchange Commission (the “Commission”) the proposed rule change as described in Items I and II below, which Items have been prepared by the self-regulatory organization. The Commission is publishing this notice to solicit comments on the proposed rule change from interested persons.

I. Self-Regulatory Organization's Statement of the Terms of Substance of the Proposed Rule Change

Pursuant to the provisions of Section 19(b)(1) of the Act,^[4] and Rule 19b-4 thereunder,^[5] the Exchange proposes to amend Rule 11.271 (“Trading Halts Due to Extraordinary Market Volatility”) concerning the resumption of trading following a Level 3 market-wide circuit breaker halt in connection with the upcoming expansion of trading by other national securities exchanges to 23 hours per day, 5 days per week. The Exchange has designated this proposal as non-controversial pursuant to Section 19(b)(3)(A)(iii) of the Act ^[6] and provided the Commission with the notice required by Rule 19b-4(f)(6)(iii) thereunder.^[7]

The text of the proposed rule change is available at the Exchange's website at www.iex.io/​resources/​regulation/​rule-filings and at the principal office of the Exchange.

II. Self-Regulatory Organization's Statement of the Purpose of, and the Statutory Basis for, the Proposed Rule Change

In its filing with the Commission, the self-regulatory organization included statements concerning the purpose of and basis for the proposed rule change and discussed any comments it received on the proposed rule change. The text of these statements may be examined at the places specified in Item IV below. The self-regulatory organization has prepared summaries, set forth in Sections A, B, and C below, of the most significant aspects of such statements.

A. Self-Regulatory Organization's Statement of the Purpose of, and the Statutory Basis for, the Proposed Rule Change

1. Purpose

The Exchange proposes to amend Rule 11.271 (“Trading Halts Due to Extraordinary Market Volatility”) concerning the resumption of trading following a Level 3 market-wide circuit breaker (“MWCB”) halt in connection with the upcoming extension of trading by other national securities exchanges to 23 hours per day, 5 days per week. Although only some exchanges will offer overnight trading, the uniform Level 3 MWCB rules of every exchange are being modified, as explained further below.

Background

The MWCB mechanism under Rule 11.271 provides an important, automatic mechanism that is invoked to promote stability and investor confidence during a period of significant stress when U.S. securities markets experience extreme broad-based declines. All U.S. equity exchanges and FINRA (collectively, the self-regulatory organizations or “SROs”) adopted uniform rules relating to the MWCB mechanism in 2012, which are designed to slow the effects of extreme price movement through coordinated trading halts across U.S. securities markets when severe price declines reach levels that may exhaust market liquidity.^[8] Currently, market-wide ( printed page 70913) circuit breaker rules provide for trading halts in all U.S. cash equities and equity options markets during a severe market decline as measured by a single-day decline in the S&P 500 Index during Regular Market Hours.

Pursuant to Rule 11.271, a market-wide trading halt will be triggered if the S&P 500 Index declines in price by specified percentages from the prior day's closing price of that index. Currently, the triggers are set at three circuit breaker thresholds: 7% (Level 1), 13% (Level 2), and 20% (Level 3). A market decline that triggers a Level 1 or Level 2 halt after 9:30 a.m. Eastern Time and before 3:25 p.m. Eastern Time would halt market-wide trading for 15 minutes, while a similar market decline at or after 3:25 p.m. Eastern Time would not halt market-wide trading. If a Level 3 Market Decline occurs at any time during the trading day, trading in all stocks will halt on the Exchange for the remainder of the trading day, and will resume the following trading day at 8:00 a.m. Eastern Time.

Proposal

The Exchange now proposes to amend Rule 11.271 to reflect the upcoming extended trading hours, i.e., 23/5 trading, that other exchanges will participate in. When 23/5 trading begins on December 6, 2026, the Exchange's current trading sessions will not change. The Exchange operates three separate trading sessions between 8:00 a.m. Eastern Time and 5:00 p.m. Eastern Time. These are the Pre-Market Session, which operates from 8:00 a.m. Eastern Time to 9:30 a.m. Eastern Time; the Regular Market Session, which operates from 9:30 a.m. Eastern Time to 4:00 p.m. Eastern Time; and the Post-Market Session, which operates from 4:00 p.m. Eastern Time to 5:00 p.m. Eastern Time.^[9] Consistent with the uniform rules in place across all SROs, current Rule 11.271(b)(2) provides that if a Level 3 MWCB occurs at any time during the trading day, trading in all stocks will halt on the Exchange for the remainder of the trading day. Currently, that means that the earliest that any exchange would re-open trading after a Level 3 MWCB is at 4:00 a.m. Eastern Time the following day, since no SROs are open for trading before 4:00 a.m. Eastern Time.

Unless amended, when 23/5 trading is launched, the current rule's reference to halting “for the remainder of the trading day” would require SROs participating in 23/5 trading to re-open trading at an earlier time, i.e., 9:00 p.m. Eastern Time on the same calendar day, when those SROs' systems would generally become available for overnight trading. The Exchange does not believe that this is an expected or desired result and is therefore amending this rule in coordination with the other SROs such that trading on any SRO will not resume until 4:00 a.m. Eastern Time or later on the following trading day, consistent with current market practice. This proposed rule change is therefore not intended to make any substantive changes to the MWCB mechanism. Rather, the proposed rule change would preserve the current resumption time following a Level 3 MWCB.

To effect this change, the Exchange proposes to delete the language in Rule 11.271(b)(2) that provides that trading in all stocks will halt on the Exchange “for the remainder of the trading day” if a Level 3 MWCB occurs at any time during the trading day, and replace it with new language that explicitly provides that trading in all stocks would halt on the Exchange until 4:00 a.m. Eastern Time or later on the following trading day.

2. Statutory Basis

The Exchange believes that the proposed rule change is consistent with the requirements of the Act and the rules and regulations thereunder that are applicable to a national securities exchange, and, in particular, with the requirements of Section 6(b) of the Act.^[10] Specifically, the Exchange believes the proposed rule change is consistent with Section 6(b)(5) of the Act ^[11] in that it is designed to promote just and equitable principles of trade, to remove impediments to, and perfect the mechanism of, a free and open market and a national market system, and, in general, to protect investors and the public interest.

The MWCB mechanism described in Rule 11.271 is an important, automatic mechanism that is invoked to promote stability and investor confidence during periods of significant stress when U.S. securities markets experience extreme broad-based declines. The proposed rule change, when applied uniformly by all SROs, would ensure that the current 4:00 a.m. Eastern Time resumption time following a Level 3 halt continues to apply under 23/5 trading, notwithstanding current rule text implying that the resumption time would coincide with the start of overnight trading on SROs operating an overnight session.

Rather than leave the rule in place as is, which would result in an earlier resumption time than originally contemplated when the rule was adopted, the Exchange, the other U.S. equity exchanges, and FINRA met alongside industry representatives to determine the appropriate resumption time. Following those discussions, the collective decision was made to retain the 4:00 a.m. Eastern Time resumption time, notwithstanding the fact that an earlier resumption time would be possible with the introduction of 23/5 trading. The proposed rule change codifies this decision into the Exchange's rules. The Exchange understands that the other SROs will also be filing similar proposed rule changes. As a result, the market as a whole, including on- and off-exchange, will continue to be subject to harmonized rules for the resumption of trading following a Level 3 MWCB.

While the SROs had previously decided to tie the resumption time following a Level 3 halt to an SRO's normal hours of operation, the upcoming transition to 23/5 trading raises various concerns that warrant a change from the current approach.

First, the Exchange notes that the MWCB mechanism was designed to provide a cooling off period where market participants would be provided with additional time to evaluate the market events that led to the decline before determining how to position their trading activity for the next day. With the introduction of 23/5 trading and the start of overnight trading on some SROs at 9:00 p.m. Eastern Time, however, this cooling-off period could be materially shortened, reducing one of the key benefits that the MWCB mechanism was designed to provide in the first place. Rather than shorten the cooling-off period and risk this benefit, the Exchange believes the market would be better served by a change to the length of the associated trading halt that mirrors current market practice. Under the proposed rule, as is the case today, after a Level 3 halt, all SROs would re-open trading at 4:00 a.m. Eastern Time or later, and no SRO would offer an overnight trading session starting on the day of a Level 3 halt.

Second, overnight trading may be subject to different liquidity and participation considerations than the current pre-market sessions that start at or after 4:00 a.m. Eastern Time. Notably, while retail investors have expressed interest in overnight trading, the Exchange expects that institutional investors will take more time to ( printed page 70914) transition to a round-the-clock model. However, such institutional participation may be of heightened importance following a Level 3 halt, as these investors are likely to have views on the underlying market events that led to the Level 3 MWCB in the first place. The Exchange is concerned that opening during hours that such participants do not normally trade may impact the quality of price discovery at a time of significant market volatility. Waiting until 4:00 a.m. Eastern Time to resume trading would facilitate broader participation and therefore price discovery.

Finally, the Exchange notes that the Commission recently approved an amendment to the Plan to Address Extraordinary Market Volatility (“LULD Plan”) that would establish new price protections from 9:00 p.m. Eastern Time to 4:00 a.m. Eastern Time.^[12] While these price bands would help to assure a fair and orderly market during normal market conditions, it is possible that they would instead prevent normal price discovery following a Level 3 MWCB. Rather than allowing trading to resume with such price bands in effect, which would represent a change from the current trading reopening following a Level 3 MWCB, the Exchange believes that requiring SROs to wait until 4:00 a.m. Eastern Time or later to resume trading would ensure that price discovery can occur unimpeded during pre-market trading, as it does today, which may further inform prices going into the opening auction and regular market hours trading following a Level 3 halt.

Given the factors discussed above, the Exchange believes that trading in all securities on the Exchange should not resume before 4:00 a.m. Eastern Time on the trading day after a Level 3 halt. This decision, which the Exchange understands will also be reflected in the rules of the other SROs, would promote a fair and orderly market at a time of significant market volatility, and thereby protect investors and the public interest. In addition, while the actual Level 3 resumption time would not be changing in practice—as proposed, the current resumption time and future resumption time would both be 4:00 a.m. Eastern Time at the earliest—the Exchange believes that it is appropriate to amend its rules to ensure that its rules reflect the upcoming changes due to 23/5 trading. Without this change, market participants may mistakenly believe that the Exchange intends for trading to re-open on overnight trading exchanges at 9:00 p.m. Eastern Time following a Level 3 halt. The proposed rule change would therefore facilitate operational transparency while providing for a fair and orderly market.

B. Self-Regulatory Organization's Statement on Burden on Competition

The Exchange does not believe that the proposed rule change will impose any burden on competition that is not necessary or appropriate in furtherance of the purposes of the Act because the proposal would ensure the continued, uninterrupted operation of a consistent mechanism to halt trading across U.S. securities markets. Further, the Exchange understands that the other SROs intend to file proposed rule changes to ensure a consistent resumption time at 4:00 a.m. Eastern Time or later across markets. Thus, the proposed rule change will help to ensure consistency across market centers without implicating any competitive issues.

C. Self-Regulatory Organization's Statement on Comments on the Proposed Rule Change Received From Members, Participants, or Others

Written comments were neither solicited nor received.

III. Date of Effectiveness of the Proposed Rule Change and Timing for Commission Action

The Exchange has designated this rule filing as non-controversial under Section 19(b)(3)(A) of the Act ^[13] and Rule 19b-4(f)(6) thereunder.^[14] Because the proposed rule change does not: (i) significantly affect the protection of investors or the public interest; (ii) impose any significant burden on competition; and (iii) become operative for 30 days from the date on which it was filed, or such shorter time as the Commission may designate, it has become effective pursuant to Section 19(b)(3)(A) of the Act and Rule 19b-4(f)(6) thereunder.^[15]

At any time within 60 days of the filing of the proposed rule change, the Commission summarily may temporarily suspend such rule change if it appears to the Commission that such action is necessary or appropriate in the public interest, for the protection of investors, or otherwise in furtherance of the purposes of the Act. If the Commission takes such action, the Commission shall institute proceedings under Section 19(b)(2)(B) ^[16] of the Act to determine whether the proposed rule change should be approved or disapproved.

IV. Solicitation of Comments

Interested persons are invited to submit written data, views and arguments concerning the foregoing, including whether the proposed rule change is consistent with the Act. Comments may be submitted by any of the following methods:

Electronic Comments

• Use the Commission's internet comment form (www.sec.gov/​rules/​sro.shtml); or
• Send an email torule-comments@sec.gov. Please include file number SR-IEX-2026-45 on the subject line.

Paper Comments

• Send paper comments in triplicate to Secretary, Securities and Exchange Commission, 100 F Street NE, Washington, DC 20549-1090.

All submissions should refer to file number SR-IEX-2026-45. This file number should be included on the subject line if email is used. To help the Commission process and review your comments more efficiently, please use only one method. The Commission will post all comments on the Commission's internet website ( www.sec.gov/​rules/​sro.shtml). Copies of the filing will be available for inspection and copying at the principal office of the Exchange. Do not include personal identifiable information in submissions; you should submit only information that you wish to make available publicly. We may redact in part or withhold entirely from publication submitted material that is obscene or subject to copyright protection. All submissions should refer to file number SR-IEX-2026-45 and should be submitted on or before November 30, 2026.