Ownership Submission
FORM 3
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934, Section 17(a) of the Public Utility Holding Company Act of 1935 or Section 30(h) of the Investment Company Act of 1940
OMB APPROVAL
OMB Number: 3235-0104
Expires: January 31, 2005
Estimated average burden hours per response... 0.5

(Print or Type Responses)
1. Name and Address of Reporting Person *
  Blackstone Management Associates VI L.L.C.
2. Date of Event Requiring Statement (Month/Day/Year)
08/06/2012
3. Issuer Name and Ticker or Trading Symbol
KNIGHT CAPITAL GROUP, INC. [KCG]
(Last)
(First)
(Middle)
C/O THE BLACKSTONE GROUP L.P., 345 PARK AVENUE
4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
_____ Director __X__ 10% Owner
_____ Officer (give title below) _____ Other (specify below)
5. If Amendment, Date Original Filed(Month/Day/Year)
(Street)

NEW YORK, NY 10154
6. Individual or Joint/Group Filing(Check Applicable Line)
___ Form filed by One Reporting Person
_X_ Form filed by More than One Reporting Person
(City)
(State)
(Zip)
Table I - Non-Derivative Securities Beneficially Owned
1.Title of Security
(Instr. 4)
2. Amount of Securities Beneficially Owned
(Instr. 4)
3. Ownership Form: Direct (D) or Indirect (I)
(Instr. 5)
4. Nature of Indirect Beneficial Ownership
(Instr. 5)
Series A-2 Non-Voting Cumulative Perpetual Conv Pref Stock 69,629 (1) (2)
I
(See Footnotes) (3) (9) (10) (11) (12)
Series A-2 Non-Voting Cumulative Perpetual Conv Pref Stock 36 (1) (2)
I
(See Footnotes) (4) (9) (10) (11) (12)
Series A-2 Non-Voting Cumulative Perpetual Conv Pref Stock 424 (1) (2)
I
(See Footnotes) (5) (9) (10) (11) (12)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly. SEC 1473 (7-02)
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB control number.

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security
(Instr. 4)
2. Date Exercisable and Expiration Date
(Month/Day/Year)
3. Title and Amount of Securities Underlying Derivative Security
(Instr. 4)
4. Conversion or Exercise Price of Derivative Security 5. Ownership Form of Derivative Security: Direct (D) or Indirect (I)
(Instr. 5)
6. Nature of Indirect Beneficial Ownership
(Instr. 5)
Date Exercisable Expiration Date Title Amount or Number of Shares
Series A-1 Cumulative Perpetual Convertible Preferred Stock   (1)(2)   (1)(2) Class A Common Stock 11,532,005 $ (1) (2) I (See Footnotes) (6) (9) (10) (11) (12)
Series A-1 Cumulative Perpetual Convertible Preferred Stock   (1)(2)   (1)(2) Class A Common Stock 5,333 $ (1) (2) I (See Footnotes) (7) (9) (10) (11) (12)
Series A-1 Cumulative Perpetual Convertible Preferred Stock   (1)(2)   (1)(2) Class A Common Stock 70,000 $ (1) (2) I (See Footnotes) (8) (9) (10) (11) (12)

Reporting Owners

Reporting Owner Name / Address Relationships
Director 10% Owner Officer Other
Blackstone Management Associates VI L.L.C.
C/O THE BLACKSTONE GROUP L.P.
345 PARK AVENUE
NEW YORK, NY 10154
    X    
Blackstone Capital Partners VI L.P.
C/O THE BLACKSTONE GROUP L.P.
345 PARK AVENUE,
NEW YORK, NY 10154
    X    
Blackstone Family Investment Partnership VI L.P.
C/O THE BLACKSTONE GROUP L.P.
345 PARK AVENUE,
NEW YORK, NY 10154
    X    
Blackstone Family Investment Partnership VI ESC L.P.
C/O THE BLACKSTONE GROUP L.P.
345 PARK AVENUE,
NEW YORK, NY 10154
    X    
BMA VI L.L.C.
C/O THE BLACKSTONE GROUP L.P.
345 PARK AVENUE,
NEW YORK, NY 10154
    X    
BCP VI Side-By-Side GP L.L.C.
C/O THE BLACKSTONE GROUP L.P.
345 PARK AVENUE,
NEW YORK, NY 10154
    X    

Signatures

BLACKSTONE CAPITAL PARTNERS VI L.P., By: Blackstone Management Associates VI, L.L.C., its general partner, By: BMA VI, L.L.C., its managing member, By: /s/ John G. Finley, Name: John G. Finley, Title: Chief Legal Officer 08/16/2012
**Signature of Reporting Person Date

BLACKSTONE FAMILY INVESTMENT PARTNERSHIP VI L.P., By: BCP VI Side-by-Side GP, L.L.C., its general partner, By: /s/ John G. Finley, Name: John G. Finley, Title: Chief Legal Officer 08/16/2012
**Signature of Reporting Person Date

BLACKSTONE FAMILY INVESTMENT PARTNERSHIP VI ESC L.P., By: BCP VI Side-by-Side GP, L.L.C., its general partner, By: /s/ John G. Finley, Name: John G. Finley, Title: Chief Legal Officer 08/16/2012
**Signature of Reporting Person Date

BLACKSTONE MANAGEMENT ASSOCIATES VI L.L.C., By: BMA VI, L.L.C., its managing member, By: /s/ John G. Finley, Name: John G. Finley, Title: Chief Legal Officer 08/16/2012
**Signature of Reporting Person Date

BMA VI L.L.C., By: /s/ John G. Finley, Name: John G. Finley, Title: Chief Legal Officer 08/16/2012
**Signature of Reporting Person Date

BCP VI SIDE-BY-SIDE GP L.L.C., By: /s/ John G. Finley, Name: John G. Finley, Title: Chief Legal Officer 08/16/2012
**Signature of Reporting Person Date

Explanation of Responses:

* If the form is filed by more than one reporting person, see Instruction 5(b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations. See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
(1) The Blackstone Funds (as defined below) beneficially own, in the aggregate, 17,411 shares of Series A-1 Cumulative Perpetual Convertible Preferred Stock, par value $0.01 per share (the "Series A-1 Preferred Stock") (convertible in accordance with the terms thereof at an initial conversion rate of 666.667 shares of Class A Common Stock, par value $0.01 per share (the "Common Stock"), per $1,000 of stated value of Series A-1 Preferred Stock, equal to an equivalent conversion price of $1.50 per share, into approximately 11,607,339 shares of Class A Common Stock, subject to certain adjustments), and 70,089 shares of Series A-2 Non-Voting Cumulative Perpetual Convertible Preferred Stock, par value $0.01 per share (the "Series A-2 Preferred Stock," and, with the Series A-1 Preferred Stock, the "Preferred Stock") (Continued in footnote 2)
(2) (convertible in accordance with the terms thereof, upon the occurrence of certain regulatory approvals, on a one-for-one basis into Series A-1 Preferred Stock or, at an initial conversion rate of 666.667 shares of Class A Common Stock per $1,000 of stated value of Series A-2 Preferred Stock, equal to an equivalent conversion price of $1.50 per share, into approximately 46,726,023 shares of Class A Common Stock, subject to certain adjustments). There is no expiration date. For further information on the events that trigger conversions and other details regarding the conversions, see the terms of the Certificate of Designations of Preferences and Rights of the Series A-1 Cumulative Perpetual Convertible Preferred Stock and Series A-2 Non-Voting Cumulative Perpetual Convertible Preferred Stock of Knight Capital Group, Inc. (attached as Exhibit 3.1 to Form 8-K filed with the Securities and Exchange Commission by the Issuer on August 6, 2012).
(3) Represents shares of Series A-2 Preferred Stock directly held by Blackstone Capital Partners VI L.P.
(4) Represents shares of Series A-2 Preferred Stock directly held by Blackstone Family Investment Partnership VI L.P.
(5) Represents shares of Series A-2 Preferred Stock directly held by Blackstone Family Investment Partnership VI ESC L.P.
(6) Represents 17,298 shares of Series A-1 Preferred Stock directly held by Blackstone Capital Partners VI L.P.
(7) Represents 8 shares of Series A-1 Preferred Stock directly held by Blackstone Family Investment Partnership VI L.P.
(8) Represents 105 shares of Series A-1 Preferred Stock directly held by Blackstone Family Investment Partnership VI ESC L.P. (collectively, with Blackstone Capital Partners VI L.P. and Blackstone Family Investment Partnership VI L.P., the "Blackstone Funds").
(9) Blackstone Management Associates VI L.L.C. is the general partner of Blackstone Capital Partners VI L.P. BMA VI L.L.C. is the sole member of Blackstone Management Associates VI L.L.C. BCP VI Side-By-Side GP L.L.C. is the general partner of Blackstone Family Investment Partnership VI L.P. and Blackstone Family Investment Partnership VI ESC L.P.
(10) Blackstone Holdings III L.P. is the managing member and the owner of a majority in interest of BMA VI L.L.C. and the sole member of BCP VI Side-By-Side GP L.L.C. Blackstone Holdings III GP L.P. is the general partner of Blackstone Holdings III L.P. The general partner of Blackstone Holdings III GP L.P. is Blackstone Holdings III GP Management L.L.C. The sole member of Blackstone Holdings III GP Management L.L.C. is The Blackstone Group L.P. The general partner of The Blackstone Group L.P. is Blackstone Group Management L.L.C. Blackstone Group Management L.L.C. is wholly owned by Blackstone's senior managing directors and controlled by its founder, Stephen A. Schwarzman.
(11) Due to the limitations of the electronic filing system, Blackstone Holdings III L.P., Blackstone Holdings III GP L.P., Blackstone Holdings III GP Management L.L.C., The Blackstone Group L.P., Blackstone Group Management L.L.C. and Stephen A. Schwarzman are filing a separate Form 3.
(12) Each of the Reporting Persons, other than the Blackstone Funds to the extent of their direct holdings, disclaims beneficial ownership of such Preferred Stock, except to the extent of such Reporting Person's pecuniary interest therein, and, pursuant to Rule 16a-1(a)(4) under the Securities Exchange Act of 1934, each of the Reporting Persons, including the Blackstone Funds, states that the inclusion of these shares in this report shall not be deemed an admission of beneficial ownership of all of the reported shares for purposes of Section 16 or for any other purpose.

Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, See Instruction 6 for procedure.

Potential persons who are to respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB number.