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
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(Print or Type Responses)
1. Name and Address of Reporting Person *
  Echinus Advisors, LLC
2. Date of Event Requiring Statement (Month/Day/Year)
04/18/2019
3. Issuer Name and Ticker or Trading Symbol
Interactive Brokers Group, Inc. [IBKR]
(Last)
(First)
(Middle)
63 CROSBY STREET, 4TH FLOOR
4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)
__X__ Director _____ 10% Owner
_____ Officer (give title below) __X__ Other (specify below)
See Remarks
5. If Amendment, Date Original Filed(Month/Day/Year)
(Street)

NEW YORK, NY 10012
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)
Class A Common Stock, par value $0.01 per share 2,411,525
I
See footnote (1)

Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly. SEC 1473 (7-02)
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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

Reporting Owners

Reporting Owner Name / Address Relationships
Director 10% Owner Officer Other
Echinus Advisors, LLC
63 CROSBY STREET
4TH FLOOR
NEW YORK, NY 10012
  X     See Remarks
Uhde Philip
63 CROSBY STREET, 4TH FLOOR
NEW YORK, NY 10012
  X     See Remarks

Signatures

/s/ Philip Uhde 04/25/2019
**Signature of Reporting Person Date

Echinus Advisors, LLC: by /s/ Philip Yang, its Chief Financial Officer & Chief Compliance Officer 04/25/2019
**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) These securities are held for the account of Echinus Partners, LP, a Delaware limited partnership (the "Echinus Fund"). Echinus Advisors, LLC, a Delaware limited liability Company ("Echinus"), serves as the investment manager to the Echinus Fund. Mr. Philip Uhde ("Mr. Uhde") is the manager and majority controlling person of Echinus. In such capacities, each of Echinus and Mr. Uhde may be deemed to beneficially own the securities herein. Each Reporting Person disclaims beneficial ownership of the securities reported herein except to the extent of his or its pecuniary interest therein, if any.
 
Remarks:
Echinus may be deemed a director by deputization of the Issuer by virtue of the fact that Mr. Uhde, currently serves on the board of directors of the Issuer.

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