Self-Regulatory Organizations; Chicago Stock Exchange, Inc.; Notice of Filing of Proposed Change To Add All NMS Stocks to the Single Securities Circuit Breaker Pilot Program

Pursuant to Section 19(b)(1) of the Securities Exchange Act of 1934 (“Act”), and Rule 19b-4 thereunder, notice is hereby given that on May 4, 2011, the Chicago Stock Exchange, Inc. (“CHX” or the “Exchange”) filed with the Securities and Exchange Commission (“Commission”) the proposed rule change as described in Items I and II below, which Items have been prepared by the CHX. 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

CHX proposes to amend CHX Article 20, Rule 2 to add all NMS stocks to the pilot program relating to individual securities circuit breakers and amend CHX Article 16, Rule 8 to simplify certain aspects of the text while also conforming certain of the percentages thereunder to CHX Article 20, Rule 2. The text of this proposed rule change is available on the Exchange's Web site at ( http://www.chx.com ) and in the Commission's Public Reference Room.

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 CHX included statements concerning the purpose of and basis for the proposed rule changes and discussed any comments it received regarding the proposal. The text of these statements may be examined at the places specified in Item IV below. The CHX 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 CHX Article 20, Rule 2 to include additional securities in the pilot by which such rule operates, to specify the thresholds used by the primary listing markets in determining when to pause trading and to amend CHX Article 16, Rule 8 to simplify certain aspects of the text while also conforming certain of the percentages thereunder to CHX Article 20, Rule 2.

The Commission approved amendments to CHX Article 20, Rule 2 on a pilot basis on June 10, 2010 to provide for trading pauses in individual securities due to extraordinary market volatility (“Trading Pause”) in all securities included within the S&P 500® Index (“S&P 500”) (“Trading Pause Pilot” or “Pilot”). The Exchange noted in its filing to adopt amendments to CHX Article 20, Rule 2 that during the Pilot period it would continue to assess whether additional securities need to be added and whether the parameters of CHX Article 20, Rule 2 would need to be modified to accommodate trading characteristics of different securities. The Exchange subsequently received approval to add to the Pilot the securities included in the Russell 1000® Index (“Russell 1000”) and a specified list of Exchange Traded Products (“ETPs”).

The Exchange has continued to assess whether additional securities need to be added to the Pilot and whether the parameters of CHX Article 20, Rule 2 need to be modified to accommodate trading characteristics of different securities. In consultation with other markets and the staff of the Commission, the Exchange proposes to include all NMS stocks within the Pilot that are not already included therein. The Exchange is also proposing to amend the text of CHX Article 20, Rule 2 to specify the thresholds used by the primary listing markets in determining when to pause trading.

In particular, the proposed additional stocks are those not currently included in the S&P 500 Index, Russell 1000 Index, or specified ETPs, and therefore are more likely to be less liquid securities or securities with lower trading volumes. Accordingly, the Exchange believes that broader Threshold Move percentages would be appropriate. Similarly, because leveraged ETPs trade at a ratio against the associated index, a broader Threshold Move percentage would also be appropriate for leveraged ETPs. Additionally, in those instances where such securities are priced below $1 and price movements equate to a higher percentage move, the Exchange believes that an even broader Threshold Move percentage is appropriate.

The proposed changes to the Pilot, if approved, would also require that the text of Article 16, Rule 8, which pertains to the pricing obligations that Market Makers are required to adhere to, be amended to adopt cross-references therein to CHX Article 20, Rule 2 and the Threshold Move thereunder. Specifically, the Exchange proposes to remove any text from CHX Article 16, Rule 8 addressing NMS stocks that are not subject to the Pilot because no such securities would exist and such text would therefore be unnecessary. The Exchange also proposes to simplify CHX Article 16, Rule 8 by explicitly stating the percentages that are applicable thereunder and the times during the trading day when stock pause triggers are not in effect under CHX Article 20, Rule 2 (or comparable rule of another exchange). The Exchange notes that part of this proposed change would be substantive, in that the percentages under CHX Article 16, Rule 8 would decrease slightly for the proposed new securities priced at $1 or greater. The Exchange believes that this proposed substantive change would not have a significant impact on Market Maker pricing obligations and is reasonable because it would ensure that the designated quoting percentages in CHX Article 16, Rule 8 are within a narrower range than the percentages necessary to trigger a Trading Pause.

2. Statutory Basis

The proposed rule change is consistent with Section 6(b) of the Act, in general, and furthers the objectives of Section 6(b)(5), in particular, in that it is 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 facilitating transactions in securities, and to remove impediments to and perfect the mechanism of a free and open market and a national market system. The proposed rule change also is designed to support the principles of Section 11A(a)(1) of the Act in that it seeks to ensure fair competition among brokers and dealers and among exchange markets. The Exchange believes that the proposed rule meets these requirements because it expands the scope of the Pilot to cover all NMS stocks while adjusting the parameters of the rule for different securities in a manner that will promote uniformity across markets concerning decisions to pause trading in a security when there are significant price movements. Additionally, the proposed changes would ensure that the designated quoting percentages in CHX Article 16, Rule 8 are within a narrower range than the percentages necessary to trigger a Trading Pause.

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.

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

No written comments were either solicited or received.

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

Within 45 days of the date of publication of this notice in the Federal Register or within such longer period (i) as the Commission may designate up to 90 days of such date if it finds such longer period to be appropriate and publishes its reasons for so finding or (ii) as to which the self-regulatory organization consents, the Commission will:

(A) By order approve or disapprove such proposed rule change, or

(B) institute proceedings to determine whether the proposed rule change should be 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 ( http://www.sec.gov/rules/sro.shtml ); or
• Send an e-mail to rule-comments@sec.gov. Please include File Number SR-CHX-2011-09 on the subject line.

Paper Comments

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

All submissions should refer to File Number SR-CHX-2011-09. This file number should be included on the subject line if e-mail 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 Web site ( http://www.sec.gov/rules/sro.shtml ). Copies of the submission, all subsequent amendments, all written statements with respect to the proposed rule change that are filed with the Commission, and all written communications relating to the proposed rule change between the Commission and any person, other than those that may be withheld from the public in accordance with the provisions of 5 U.S.C. 552, will be available for Web site viewing and printing in the Commission's Public Reference Room, 100 F Street, NE., Washington, DC 20549, on official business days between the hours of 10 a.m. and 3 p.m. Copies of such filing also will be available for inspection and copying at the principal office of the Exchange. All comments received will be posted without change; the Commission does not edit personal identifying information from submissions. You should submit only information that you wish to make publicly available. All submissions should refer to File Number SR-CHX-2011-09 and should be submitted on or before June 2, 2011.