Notice2025-22142
Self-Regulatory Organizations; MEMX LLC; Notice of Filing and Immediate Effectiveness of a Proposal To Amend Exchange Rule 11.6(q)(1), Round Lot, To Conform With the Amendment to the Definition of Round Lot Under Rule 600 of Regulation NMS Recently Approved by the Commission
Primary source
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Published
December 8, 2025
Issuing agencies
Securities and Exchange Commission
Full Text
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<title>Federal Register, Volume 90 Issue 233 (Monday, December 8, 2025)</title>
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[Federal Register Volume 90, Number 233 (Monday, December 8, 2025)]
[Notices]
[Pages 56807-56809]
From the Federal Register Online via the Government Publishing Office [<a href="http://www.gpo.gov">www.gpo.gov</a>]
[FR Doc No: 2025-22142]
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SECURITIES AND EXCHANGE COMMISSION
[Release No. 34-104300; File No. SR-MEMX-2025-33]
Self-Regulatory Organizations; MEMX LLC; Notice of Filing and
Immediate Effectiveness of a Proposal To Amend Exchange Rule
11.6(q)(1), Round Lot, To Conform With the Amendment to the Definition
of Round Lot Under Rule 600 of Regulation NMS Recently Approved by the
Commission
December 3, 2025.
Pursuant to Section 19(b)(1) of the Securities Exchange Act of 1934
(the ``Act''),\1\ and Rule 19b-4 thereunder,\2\ notice is hereby given
that on November 25, 2025, MEMX LLC (``MEMX'' 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 Exchange. The Exchange filed the
proposal as a ``non-controversial'' proposed rule change pursuant to
Section 19(b)(3)(A)(iii) of the Act \3\ and Rule 19b-4(f)(6)
thereunder.\4\ The Commission is publishing this notice to solicit
comments on the proposed rule change from interested persons.
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\1\ 15 U.S.C. 78s(b)(1).
\2\ 17 CFR 240.19b-4.
\3\ 15 U.S.C. 78s(b)(3)(A).
\4\ 17 CFR 240.19b-4.
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I. Self-Regulatory Organization's Statement of the Terms of Substance
of the Proposed Rule Change
The Exchange is filing with the Commission a proposed rule change
to amend Rule 11.6(q)(1), Round Lot, to conform with a recent amendment
to the definition of round lot under Rule 600 of Regulation NMS
recently approved by the Commission.\5\ The Exchange also proposes to
make conforming, non-substantive changes to Exchange Rules
11.9(b)(2)(A)-(D) and Exchange Rule 11.20(d)(1). The text of the
proposed rule change is provided in Exhibit 5 and is available on the
Exchange's website at <a href="https://info.memxtrading.com/regulation/rules-and-filings/">https://info.memxtrading.com/regulation/rules-and-filings/</a>.
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\5\ See Securities Exchange Act Release No. 101070 (September
18, 2024), 89 FR 81620 (October 8, 2024) (S7-30-22).
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II. Self-Regulatory Organization's Statement of the Purpose of, and
Statutory Basis for, the Proposed Rule Change
In its filing with the Commission, the Exchange 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 Exchange 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
Statutory Basis for, the Proposed Rule Change
1. Purpose
The Exchange proposes to amend Rule 11.6(q)(1), Round Lot, to
conform with the definition of round lot under Rule 600 of the
Regulation NMS that is to be implemented in November 2025.\6\ The
Exchange also proposes to make conforming non-substantive changes to
Rules 11.9(b)(2)(A)-(D), Priority of Orders, Dissemination, and Rule
11.20(d)(1), Continuous, Two-Sided Quote Obligation.
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\6\ See supra note 5.
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In 2020, the Commission adopted amendments to Regulation NMS to
modernize the NMS information provided within the national market
system for the benefit of market participants and to better achieve
Section 11A's goals of assuring ``the availability to brokers, dealers,
and investors of information with respect to quotations for and
transactions in securities that is prompt, accurate, reliable, and
fair'' (``MDI Rules'').\7\ These changes included an amendment to Rule
600 of Regulation NMS to include a definition of ``round lot'' that
assigns each NMS stock to a round lot size based on the stock's average
closing price.\8\ Prior to this change, a ``round lot'' was not defined
in the Act or Regulation NMS. The definition of a ``round lot'' was
included in the rules of the individual exchanges, including Exchange
Rule 11.6(q)(1), which defined a ``Round Lot'' as 100 shares or any
multiple thereof, but the rules also generally allowed the exchanges,
or the primary listing exchange for the security, discretion to define
``round lot'' otherwise.
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\7\ See Securities Exchange Act Release No. 90610 (December 9,
2020), 86 FR 18596 (April 9, 2021) (``MDI Adopting Release'').
\8\ See id.
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On September 18, 2024, the Commission accelerated the
implementation of the round lot definition.\9\ The Commission also
revised the round lot definition as set forth below.\10\ Rule
600(b)(93) of Regulation NMS, as adopted by the MDI Rules and as
amended in 2024,\11\ defines a round lot for NMS stocks \12\ that have
an average closing price on the primary listing exchange during the
prior Evaluation Period \13\ of: (1) $250.00 or less per share as 100
shares; (2) $250.01 to $1,000.00 per share as 40 shares; (3) $1,000.01
to $10,000.00 per share as 10 shares; and (4) $10,000.01 or more per
share as 1 share.\14\ For any security that becomes an NMS Stock during
an operative period, as described in Rule 600(b)(93)(iv),\15\ a round
lot is 100 shares. Adjustments to the round lot size for a security
will occur on a semiannual basis and the calculation of the average
closing price on the primary listing exchange will be based on a one
month ``Evaluation Period.'' \16\ The revised definition of round lot
is to be implemented on November 3, 2025, the first business day of
November 2025.\17\
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\9\ See supra note 5.
\10\ See supra note 5.
\11\ See supra note 5.
\12\ ``NMS stock'' is defined under Regulation NMS as any NMS
security other than an option. 17 CFR 242.600(b)(65).
\13\ Rule 600(b)(93)(iii) of Regulation NMS defines the
Evaluation Period as ``(A) all trading days in March for the round
lot assigned on the first business day in May and (B) all trading
days in September for the round lot assigned on the first business
day of November during which the average closing price of an NMS
stock on the primary listing exchange shall be measured by the
primary listing exchange to determine the round lot for each NMS
stock.''
\14\ See supra note 5.
\15\ Pursuant to Rule 600(b)(93)(iv) of Regulation NMS the round
lot assigned under the section ``shall be operative on (A) the first
business day of May for the March Evaluation Period and continue
through the last business day of October of the calendar year, and
(B) the first business day of November for the September Evaluation
Period and continue through the last business day of April of the
next calendar year.''
\16\ See supra note 5.
\17\ See supra note 5.
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The Exchange now proposes to amend Exchange Rule 11.6(q)(1), Round
Lot, to conform with the definition of round lot under Rule 600 of the
Regulation NMS. Exchange Rule 11.6(q)(1) provides that ``[O]ne hundred
(100) shares or any multiple thereof shall constitute a Round Lot,
unless an alternative number of shares is established as a Round Lot by
the listing exchange for the security.'' The Exchange now
[[Page 56808]]
proposes to replace this sentence with a sentence that explicitly
refers to the definition of round lot under Rule 600 of Regulation NMS.
As a result, the above sentence will be deleted and replaced with the
following, ``[a] Round Lot for each NMS Stock shall be the size
assigned by the primary listing market pursuant to Rule 600 of
Regulation NMS under the Exchange Act.'' Again, this change is being
proposed solely to conform the Exchange's definition of ``Round Lot''
under Exchange Rule 11.6(q)(1) to the new definition of Round Lot under
Rule 600 of Regulation NMS.
The Exchange also proposes to make conforming non-substantive
changes to Exchange Rules 11.9(b)(2)(A)-(D), Priority of Orders,
Dissemination, and Exchange Rule 11.20(d)(1), Continuous, Two-Sided
Quote Obligation. The Exchange proposes to capitalize the term ``round
lot'' in Rule 11.9(b)(2)(A)-(D). In addition, the Exchange proposes to
amend Exchange Rule 11.20(d)(1) to conform with the Exchange's
definition of Round Lot. Exchange Rule 11.20(d)(1) currently provides
that ``[u]nless otherwise designated, a `normal unit of trading' shall
be 100 shares.'' The Exchange proposes to replace the aforementioned
sentence with a sentence that conforms to the newly adopted definition
of Round Lot in the Exchange's Rulebook. As a result, the above
sentence will be deleted and replaced with the following: ``[u]nless
otherwise designated, a `normal unit of trading' shall be a Round Lot
as defined in Exchange Rule 11.6(q)(1).''
The purpose of these changes is to provide greater clarity to
Exchange Members \18\ and the public regarding the Exchange's Rulebook.
The Exchange does not propose any additional rule changes. The proposed
rule changes will be implemented immediately.
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\18\ See Exchange Rule 1.5(p). A ``Member'' is defined as ``any
registered broker or dealer that has been admitted to membership in
the Exchange.''
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2. Statutory Basis
The Exchange believes the proposed rule changes are consistent with
the Securities Exchange Act of 1934 (the ``Act'') and the rules and
regulations thereunder applicable to the Exchange and, in particular,
the requirements of Section 6(b) of the Act.\19\ Specifically, the
Exchange believes the proposed rule changes are consistent with the
Section 6(b)(5) \20\ requirements that the rules of an exchange be
designed to prevent fraudulent and manipulative acts and practices, to
promote just and equitable principles of trade, to foster cooperation
and coordination with persons engaged in regulating, clearing,
settling, processing information with respect to, and facilitating
transactions in securities, 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. Additionally,
the Exchange believes the proposed rule changes are consistent with the
Section 6(b)(5) \21\ requirement that the rules of an exchange not be
designed to permit unfair discrimination between customers, issuers,
brokers, or dealers.
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\19\ 15 U.S.C. 78f(b).
\20\ 15 U.S.C. 78f(b)(5).
\21\ Id.
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The Exchange proposes to amend Exchange Rule 11.6(q)(1), Round Lot,
to conform with the definition of round lot under Rule 600 of the
Regulation NMS that is to be implemented in November 2025.\22\ This
change is proposed solely to conform the Exchange's definition of
``Round Lot'' under Exchange Rule 11.6(q)(1) to the new definition of
Round Lot under Rule 600 of Regulation NMS. The Exchange also proposes
to make conforming, non-substantive changes to Exchange Rules
11.9(b)(2)(A)-(D), Priority of Orders, Dissemination, and Exchange Rule
11.20(d)(1), Continuous, Two-Sided Quote Obligation. These changes are
limited to capitalizing the term ``round lot'' in Exchange Rules
11.9(b)(2)(A)-(D) and amending Exchange Rule 11.20(d)(1) to conform
with the Exchange's definition of round lot.
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\22\ See supra note 5.
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The proposed changes do not amend the operation of the affected
rules. The proposed rule changes would reduce potential investor and
market participant confusion and therefore remove impediments to and
perfect the mechanism of a free and open market and a national market
system by ensuring that the Exchange's rules properly reflect the
requirements of Rule 600 of Regulation NMS. The Exchange also believes
that the proposed rule changes would remove impediments to and perfect
the mechanism of a free and open market by ensuring that persons
subject to the Exchange's jurisdiction, regulators, and the investing
public can more easily navigate and understand the Exchange's rules.
The proposed rule changes would not be inconsistent with the public
interest or the protection of investors because investors will not be
harmed and, in fact, would benefit from the increased transparency and
clarity, thereby reducing potential confusion.
B. Self-Regulatory Organization's Statement on Burden on Competition
The Exchange does not believe that the proposed rule changes will
impose any burden on competition that is not necessary or appropriate
in furtherance of the purposes of the Act. The proposed rule change to
amend the definition of round lot is not intended to address
competitive issues; rather, the proposed change is concerned solely
with amending the Exchange's Rule to conform with the definition of
round lot under Rule 600 of the Regulation NMS. The proposed rule
changes to capitalize the term ``round lot'' in Exchange Rules
11.9(b)(2)(A)-(D) and amend Exchange Rule 11.20(d)(1) to conform with
the Exchange's definition of round lot are conforming and non-
substantive in nature, and are not intended to address competitive
issues.
C. Self-Regulatory Organization's Statement on Comments on the Proposed
Rule Change Received From Members, Participants, or Others
The Exchange neither solicited nor received comments on the
proposed rule change.
III. Date of Effectiveness of the Proposed Rule Change and Timing for
Commission Action
The proposed rule change is filed for immediate effectiveness
pursuant to Section 19(b)(3)(A) of Act \23\ and Rule 19b-4(f)(6) \24\
thereunder. The Exchange designates that the proposed rule change
effects a change that (i) does not significantly affect the protection
of investors or the public interest; (ii) does not impose any
significant burden on competition; and (iii) by its terms, does not
become operative for 30 days after the date of the filing, or such
shorter time as the Commission may designate if consistent with the
protection of investors and the public interest.\25\
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\23\ 15 U.S.C. 78s(b)(3)(A).
\24\ 17 CFR 240.19b-4(f)(6).
\25\ In addition, Rule 19b-4(f)(6)(iii) requires the Exchange to
give the Commission written notice of the Exchange's intent to file
the proposed rule change, along with a brief description and text of
the proposed rule change, at least five business days prior to the
date of filing of the proposed rule change, or such shorter time as
designated by the Commission. The Exchange has satisfied this
requirement.
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A proposed rule change filed under Rule 19b-4(f)(6) normally may
not become operative prior to 30 days after the date of filing.
However, Rule 19b-4(f)(6)(iii) \26\ permits the Commission to designate
a shorter time if such action is consistent with the protection of
investors and the public interest. The
[[Page 56809]]
Exchange has requested that the Commission waive the 30-day operative
delay period. The Commission believes that waiver of the 30-day
operative delay period is consistent with the protection of investors
and the public interest. Specifically, the proposal would conform the
Exchange's definition of round lot with Rule 600 of Regulation NMS and
would make other non-substantive changes. The Commission believes that
the proposal would reduce potential investor and market participant
confusion by aligning the Exchange's definition of round lot with
Regulation NMS's definition. For these reasons, the Commission believes
that waiving the 30-day operative delay is consistent with the
protection of investors and the public interest, and designates the
proposed rule change to be operative upon filing with the
Commission.\27\
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\26\ 17 CFR 240.19b-4(f)(6)(iii).
\27\ For purposes only of waiving the operative delay for this
proposal, the Commission has considered the proposed rule's impact
on efficiency, competition, and capital formation. See 15 U.S.C.
78c(f).
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At any time within 60 days of the filing of this 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 will institute proceedings 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
<bullet> Use the Commission's internet comment form (<a href="https://www.sec.gov/rules/sro.shtml">https://www.sec.gov/rules/sro.shtml</a>); or
<bullet> Send an email to <a href="/cdn-cgi/l/email-protection#681a1d040d450b0705050d061c1b281b0d0b460f071e"><span class="__cf_email__" data-cfemail="3341465f561e505c5e5e565d4740734056501d545c45">[email protected]</span></a>. Please include
file number SR-MEMX-2025-33 on the subject line.
Paper Comments
<bullet> 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-MEMX-2025-33. 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 (<a href="https://www.sec.gov/rules/sro.shtml">https://www.sec.gov/rules/sro.shtml</a>). 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-MEMX-2025-33 and
should be submitted on or before December 29, 2025.
For the Commission, by the Division of Trading and Markets,
pursuant to delegated authority.\28\
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\28\ 17 CFR 200.30-3(a)(12) and (59).
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Sherry R. Haywood,
Assistant Secretary.
[FR Doc. 2025-22142 Filed 12-5-25; 8:45 am]
BILLING CODE 8011-01-P
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