<SEC-DOCUMENT>0001381197-16-000080.txt : 20160803
<SEC-HEADER>0001381197-16-000080.hdr.sgml : 20160803
<ACCEPTANCE-DATETIME>20160802183304
ACCESSION NUMBER:		0001381197-16-000080
CONFORMED SUBMISSION TYPE:	SC 13D/A
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20160803
DATE AS OF CHANGE:		20160802
GROUP MEMBERS:		THOMAS PETERFFY

SUBJECT COMPANY:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			Interactive Brokers Group, Inc.
		CENTRAL INDEX KEY:			0001381197
		STANDARD INDUSTRIAL CLASSIFICATION:	SECURITY BROKERS, DEALERS & FLOTATION COMPANIES [6211]
		IRS NUMBER:				000000000
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13D/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-82876
		FILM NUMBER:		161801829

	BUSINESS ADDRESS:	
		STREET 1:		ONE PICKWICK PLAZA
		CITY:			GREENWICH
		STATE:			CT
		ZIP:			06830
		BUSINESS PHONE:		203-618-5800

	MAIL ADDRESS:	
		STREET 1:		ONE PICKWICK PLAZA
		CITY:			GREENWICH
		STATE:			CT
		ZIP:			06830

FILED BY:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			IBG Holdings LLC
		CENTRAL INDEX KEY:			0001399812
		IRS NUMBER:				352296543
		STATE OF INCORPORATION:			DE
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SC 13D/A

	BUSINESS ADDRESS:	
		STREET 1:		ONE PICKWICK PLAZA
		CITY:			GREENWICH
		STATE:			CT
		ZIP:			06830
		BUSINESS PHONE:		2036185800

	MAIL ADDRESS:	
		STREET 1:		ONE PICKWICK PLAZA
		CITY:			GREENWICH
		STATE:			CT
		ZIP:			06830
</SEC-HEADER>
<DOCUMENT>
<TYPE>SC 13D/A
<SEQUENCE>1
<FILENAME>ibgholdings-13d_a4.htm
<DESCRIPTION>SC 13 D/A
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<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="center"><font style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; FONT-WEIGHT: bold; DISPLAY: inline">Interactive Brokers Group, Inc.</font></div>
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<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="center"><font style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; DISPLAY: inline">(Name of Issuer)</font></div>

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<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="center"><font style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; DISPLAY: inline">Thomas Peterffy</font></div>

<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="center"><font style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; DISPLAY: inline">IBG Holdings LLC</font></div>

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<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="center"><font style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; DISPLAY: inline">Greenwich, CT 06830</font></div>

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<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="center"><font style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; DISPLAY: inline">Richard Goldberg, Esq.</font></div>

<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="center"><font style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; DISPLAY: inline">Dechert LLP</font></div>

<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="center"><font style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; DISPLAY: inline">1095 Avenue of the Americas</font></div>

<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="center"><font style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; DISPLAY: inline">New York, NY 10036</font></div>

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<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="center"><font style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; DISPLAY: inline">(Name, Address and Telephone Number of Person</font></div>

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<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 36pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; DISPLAY: inline">If the filing person has previously filed a statement on Schedule 13G to report the acquisition which is the subject of this Schedule 13D, and is filing this schedule because of Sections 240.13d-1(e), 240.13d-1(f) or 240.13d-1(g), check the following box. [&#160;&#160;&#160;]</font></div>

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<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 36pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; DISPLAY: inline"><font style="FONT-WEIGHT: bold; DISPLAY: inline">Note:</font> Schedules filed in paper format shall include a signed original and five copies of the schedule, including all exhibits. &#160;See Section 240.13d-7 for other parties to whom copies are to be sent.</font></div>

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<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 36pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; DISPLAY: inline">*The remainder of this cover page shall be filled out for a reporting person&#8217;s initial filing on this form with respect to the subject class of securities, and for any subsequent amendment containing information which would alter disclosures provided in a prior cover page.</font></div>

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<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="center"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">1.</font></div>
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<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">&#160;Names of Reporting Person</font></div>

<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; FONT-WEIGHT: bold; DISPLAY: inline">&#160;IBG Holdings LLC</font></div>

<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; FONT-WEIGHT: bold; DISPLAY: inline">&#160;I.R.S. Identification No. 35-2296543</font></div>

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<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="center"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">2.</font></div>
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<div><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">&#160;&#160; &#160; Check the Appropriate Box if a Member of a Group (See</font></div>

<div><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">&#160;&#160;&#160; &#160;Instructions)&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;&#160;</font></div>
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<td align="left" valign="top" width="36%" style="BORDER-BOTTOM: black 2px solid">&#160;</td>
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<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">(a) <font style="FONT-SIZE: 10pt; DISPLAY: inline"><font style="FONT-FAMILY: wingdings; DISPLAY: inline">x</font></font></font></div>

<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">(b) <font style="FONT-FAMILY: wingdings; DISPLAY: inline">o</font></font></div>
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<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="center"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">3.</font></div>
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<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="center"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">4.</font></div>
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<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">&#160;Source of Funds (See Instructions)</font></div>

<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; FONT-WEIGHT: bold; DISPLAY: inline">&#160;OO</font></div>
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<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="center"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">5.</font></div>
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<div><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">&#160;&#160;&#160; Check if Disclosure of Legal Proceedings is Required</font></div>

<div><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">&#160;&#160;&#160; Pursuant to Items 2(d) or 2(e)&#160;&#160;&#160;&#160;&#160;&#160;&#160;</font></div>
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<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline"><font style="FONT-SIZE: 10pt; DISPLAY: inline"><font style="FONT-FAMILY: wingdings; DISPLAY: inline">o</font></font></font></div>
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<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="center"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">6.</font></div>
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<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">Citizenship or Place of Organization</font></div>

<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; FONT-WEIGHT: bold; DISPLAY: inline">Delaware, United States of America</font></div>
</td>
</tr><tr>
<td align="left" colspan="2" rowspan="4" valign="top" width="21%" style="PADDING-BOTTOM: 2px">
<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">Number of</font></div>

<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">Shares</font></div>

<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">Beneficially Owned by</font></div>

<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">Each</font></div>

<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">Reporting</font></div>

<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">Person</font></div>

<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">With</font></div>
</td>
<td valign="top" width="8%" style="BORDER-BOTTOM: black 2px solid; TEXT-ALIGN: center"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">7.&#160; </font></font></td>
<td colspan="3" valign="top" width="71%" style="BORDER-BOTTOM: black 2px solid">
<div><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">&#160; &#160; Sole Voting Power</font> </font></div>

<div><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; FONT-WEIGHT: bold; DISPLAY: inline">&#160;&#160; &#160;1,596,200 <font style="FONT-SIZE: 70%; VERTICAL-ALIGN: text-top; DISPLAY: inline">(1)</font></font><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; FONT-WEIGHT: bold; DISPLAY: inline">&#160;</font></font></div>

<div><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; FONT-WEIGHT: bold; DISPLAY: inline">&#160;&#160;&#160; 341,444,304<font style="FONT-SIZE: 70%; VERTICAL-ALIGN: text-top; DISPLAY: inline">(2)</font></font></font></div>
</td>
</tr><tr>
<td valign="top" width="8%" style="BORDER-BOTTOM: black 2px solid; TEXT-ALIGN: center"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">8.</font></font></td>
<td colspan="3" valign="top" width="71%" style="BORDER-BOTTOM: black 2px solid">
<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="center">
<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">Shared Voting Power<a name="schedule13dworkingdraft_htm_ole_link1"><!--efplaceholder--></a></font></font></div>

<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; FONT-WEIGHT: bold; DISPLAY: inline">Not applicable</font></font></div>
</div>
</td>
</tr><tr>
<td valign="top" width="8%" style="BORDER-BOTTOM: black 2px solid; TEXT-ALIGN: center"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">9.</font></font></td>
<td colspan="3" valign="top" width="71%" style="BORDER-BOTTOM: black 2px solid">
<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="center">
<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">Sole Dispositive Power</font></font></div>

<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; FONT-WEIGHT: bold; DISPLAY: inline">1,596,200 <font style="FONT-SIZE: 70%; VERTICAL-ALIGN: text-top; DISPLAY: inline">(1)</font></font></font></div>
</div>
</td>
</tr><tr>
<td valign="top" width="8%" style="BORDER-BOTTOM: black 2px solid; TEXT-ALIGN: center"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">10.</font></font></font></td>
<td colspan="3" valign="top" width="71%" style="BORDER-BOTTOM: black 2px solid">
<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="center">
<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">Shared Dispositive Power</font></font></div>

<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; FONT-WEIGHT: bold; DISPLAY: inline">Not applicable</font></font></div>
</div>
</td>
</tr><tr>
<td valign="top" width="7%" style="BORDER-BOTTOM: black 2px solid">
<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="center"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">11.</font></div>
</td>
<td colspan="5" valign="top" width="93%" style="BORDER-BOTTOM: black 2px solid">
<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="justify"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">Aggregate Amount Beneficially Owned by Each Reporting Person</font></div>

<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="justify"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; FONT-WEIGHT: bold; DISPLAY: inline">1,596,200 <font style="FONT-SIZE: 70%; VERTICAL-ALIGN: text-top; DISPLAY: inline">(1)</font></font></div>

<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="justify"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; FONT-WEIGHT: bold; DISPLAY: inline">&#160;341,444,304<font style="FONT-SIZE: 70%; VERTICAL-ALIGN: text-top; DISPLAY: inline">(2)</font></font></div>
</td>
</tr><tr>
<td valign="top" width="7%" style="BORDER-BOTTOM: black 2px solid">
<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="center"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">12.</font></div>
</td>
<td colspan="3" valign="top" width="34%" style="BORDER-BOTTOM: black 2px solid">
<div><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">&#160;&#160;&#160; Check if the Aggregate Amount in Row (11) Excludes </font></div>

<div><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">&#160;&#160;&#160; Certain Shares (See Instructions)&#160;&#160;&#160;&#160;&#160;</font></div>
</td>
<td valign="top" width="48%" style="BORDER-BOTTOM: black 2px solid"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">&#160;</font></td>
<td valign="top" width="10%" style="BORDER-BOTTOM: black 2px solid">
<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="justify"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline"><font style="FONT-SIZE: 10pt; DISPLAY: inline"><font style="FONT-FAMILY: wingdings; DISPLAY: inline">o</font></font></font></div>
</td>
</tr><tr>
<td valign="top" width="7%" style="BORDER-BOTTOM: black 2px solid">
<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="center"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">13.</font></div>
</td>
<td colspan="5" valign="top" width="93%" style="BORDER-BOTTOM: black 2px solid">
<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="justify"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">Percent of Class Represented by Amount in Row (11)</font></div>

<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: -9pt" align="justify"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; FONT-WEIGHT: bold; DISPLAY: inline">&#160;&#160; &#160;83.8%<font style="FONT-SIZE: 70%; VERTICAL-ALIGN: text-top; DISPLAY: inline">(3)</font></font></div>
</td>
</tr><tr>
<td valign="top" width="7%" style="BORDER-BOTTOM: black 2px solid">
<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="center"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">14.</font></div>
</td>
<td colspan="5" valign="top" width="93%" style="BORDER-BOTTOM: black 2px solid">
<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="justify"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">Type of Reporting Person (See Instructions)</font></div>

<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="justify"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; FONT-WEIGHT: bold; DISPLAY: inline">HC</font></div>
</td>
</tr></table>
</div>

<div style="DISPLAY: block; TEXT-INDENT: 0pt"><br>
</div>

<div style="DISPLAY: block; TEXT-INDENT: 0pt"><br>
</div>

<div align="center">
<table border="0" cellpadding="0" cellspacing="0" id="hangingindent" width="100%" style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; FONT-SIZE: 10pt; FONT-FAMILY: times new roman">
<tr valign="top">
<td width="2%" style="WIDTH: 360pt">
<div style="MARGIN-LEFT: 0pt; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">(1)</font></div>
</td>
<td width="98%">
<div align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">IBG Holdings LLC beneficially owns 1,596,200 shares of Class A Common Stock, which were acquired on July 28, 2016.</font></div>
</td>
</tr></table>
</div>

<div style="DISPLAY: block; TEXT-INDENT: 0pt"><br>
</div>

<div align="center">
<table border="0" cellpadding="0" cellspacing="0" id="hangingindent" width="100%" style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; FONT-SIZE: 10pt; FONT-FAMILY: times new roman">
<tr valign="top">
<td width="2%" style="WIDTH: 360pt">
<div style="MARGIN-LEFT: 0pt; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">(2)</font></div>
</td>
<td width="98%">
<div align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">Pursuant to the Amended and Restated Certificate of Incorporation of the issuer, IBG Holdings LLC, as the sole holder of the 100 outstanding shares of the issuer&#8217;s Class B Common Stock, is entitled to the number of votes equal to the number of IBG LLC membership interests held by it at any given time. As of the date of this statement, IBG Holdings LLC holds 341,444,304 IBG LLC membership interests.</font></div>
</td>
</tr></table>
</div>

<div style="DISPLAY: block; TEXT-INDENT: 0pt"><br>
</div>

<div align="center">
<table border="0" cellpadding="0" cellspacing="0" id="hangingindent" width="100%" style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; FONT-SIZE: 10pt; FONT-FAMILY: times new roman">
<tr valign="top">
<td width="2%" style="WIDTH: 360pt">
<div style="MARGIN-LEFT: 0pt; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">(3)</font></div>
</td>
<td width="98%">
<div align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">IBG Holdings LLC&#8217;s beneficial ownership of 1,596,200 shares of Class A Common Stock represents approximately&#160;2.4% of the outstanding shares of Class A Common Stock and approximately&#160;0.4% of the voting power of the issuer.&#160;&#160;IBG Holdings LLC&#8217;s beneficial ownership of the 100 outstanding shares of the issuer&#8217;s Class B Common Stock entitles it to approximately&#160;83.4% of the voting power of the issuer.&#160;&#160;In total, IBG Holdings LLC holds approximately&#160;83.8% of the voting power of the issuer.</font></div>
</td>
</tr></table>
</div>

<br>
<div id="PGBRK" style="MARGIN-LEFT: 0pt; WIDTH: 100%; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt">
<div id="FTR">
<div id="GLFTR" style="WIDTH: 100%" align="left"><font style="FONT-SIZE: 8pt; FONT-FAMILY: Times New Roman; DISPLAY: inline">&#160; </font></div>
</div>

<div id="PN" style="PAGE-BREAK-AFTER: always; WIDTH: 100%">
<div style="TEXT-ALIGN: center; WIDTH: 100%"><font style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; DISPLAY: inline">2</font></div>

<div style="TEXT-ALIGN: center; WIDTH: 100%">
<hr style="COLOR: black" noshade size="2">
</div>
</div>

<div id="HDR">
<div id="GLHDR" style="WIDTH: 100%" align="right"><font style="FONT-SIZE: 8pt; FONT-FAMILY: Times New Roman; DISPLAY: inline">&#160; </font></div>
</div>
</div>

<br>
<div style="DISPLAY: block; TEXT-INDENT: 0pt"><br>
</div>

<div>
<table cellpadding="0" cellspacing="0" width="100%" style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; FONT-SIZE: 10pt; FONT-FAMILY: times new roman">
<tr>
<td align="left" colspan="4" valign="top" width="45%" style="BORDER-TOP: #000000 1pt solid; BORDER-BOTTOM: black 2px solid">
<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">CUSIP Number 45841N 107</font></div>
</td>
<td align="left" valign="top" width="20%" style="BORDER-TOP: #000000 1pt solid; BORDER-BOTTOM: black 2px solid"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">&#160; </font></td>
<td align="left" colspan="2" valign="top" width="35%" style="BORDER-TOP: #000000 1pt solid; BORDER-BOTTOM: black 2px solid"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">&#160; </font></td>
</tr><tr>
<td valign="top" width="7%" style="BORDER-BOTTOM: black 2px solid">
<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="center"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">1.</font></div>
</td>
<td align="left" colspan="6" valign="top" width="93%" style="BORDER-BOTTOM: black 2px solid">
<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">&#160;Names of Reporting Person</font></div>

<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; FONT-WEIGHT: bold; DISPLAY: inline">&#160;Thomas Peterffy</font></div>
</td>
</tr><tr>
<td valign="top" width="7%" style="BORDER-BOTTOM: black 2px solid">
<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="center"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">2.</font></div>
</td>
<td align="left" colspan="3" valign="top" width="38%" style="BORDER-BOTTOM: black 2px solid">
<div><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">&#160;&#160;&#160;&#160; Check the Appropriate Box if a Member of a Group (See</font></div>

<div><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">&#160;&#160;&#160;&#160; Instructions)&#160;&#160;&#160;&#160;</font></div>
</td>
<td align="left" valign="top" width="20%" style="BORDER-BOTTOM: black 2px solid"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">&#160;</font></td>
<td align="left" valign="top" width="24%" style="BORDER-BOTTOM: black 2px solid"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">&#160;</font></td>
<td align="left" valign="top" width="11%" style="BORDER-BOTTOM: black 2px solid">
<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline"><font style="FONT-SIZE: 10pt; DISPLAY: inline">(a)</font> <font style="FONT-SIZE: 10pt; DISPLAY: inline"><font style="FONT-FAMILY: wingdings; DISPLAY: inline">x</font></font></font></div>

<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">(b) <font style="FONT-FAMILY: wingdings; DISPLAY: inline">o</font></font></div>
</td>
</tr><tr>
<td valign="top" width="7%" style="BORDER-BOTTOM: black 2px solid">
<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="center"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">3.</font></div>
</td>
<td align="left" colspan="6" valign="top" width="93%" style="BORDER-BOTTOM: black 2px solid">
<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">&#160;SEC Use Only</font></div>
</td>
</tr><tr>
<td valign="top" width="7%" style="BORDER-BOTTOM: black 2px solid">
<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="center"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">4.</font></div>
</td>
<td align="left" colspan="6" valign="top" width="93%" style="BORDER-BOTTOM: black 2px solid">
<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">&#160;Source of Funds (See Instructions)</font></div>

<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; FONT-WEIGHT: bold; DISPLAY: inline">&#160;OO</font></div>
</td>
</tr><tr>
<td valign="top" width="7%" style="BORDER-BOTTOM: black 2px solid">
<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="center"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">5.</font></div>
</td>
<td align="left" colspan="3" valign="top" width="38%" style="BORDER-BOTTOM: black 2px solid">
<div><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">&#160;&#160; &#160; Check if Disclosure of Legal Proceedings is Required </font></div>

<div><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">&#160;&#160;&#160;&#160; Pursuant to Items 2(d) or 2(e)&#160;&#160;&#160;&#160;</font></div>
</td>
<td align="left" valign="top" width="20%" style="BORDER-BOTTOM: black 2px solid"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">&#160;</font></td>
<td align="left" valign="top" width="24%" style="BORDER-BOTTOM: black 2px solid"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">&#160;</font></td>
<td align="left" valign="top" width="11%" style="BORDER-BOTTOM: black 2px solid">
<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">&#160;&#160;&#160;&#160;&#160;<font style="FONT-SIZE: 10pt; DISPLAY: inline"><font style="FONT-FAMILY: wingdings; DISPLAY: inline">o</font></font></font></div>
</td>
</tr><tr>
<td valign="top" width="7%" style="BORDER-BOTTOM: black 2px solid">
<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="center"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">6.</font></div>
</td>
<td align="left" colspan="6" valign="top" width="93%" style="BORDER-BOTTOM: black 2px solid">
<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">&#160;Citizenship or Place of Organization</font></div>

<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; FONT-WEIGHT: bold; DISPLAY: inline">&#160;United States of America</font></div>
</td>
</tr><tr>
<td align="left" colspan="2" rowspan="4" valign="top" width="22%" style="PADDING-BOTTOM: 2px">
<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">Number of</font></div>

<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">Shares</font></div>

<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">Beneficially Owned by</font></div>

<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">Each</font></div>

<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">Reporting</font></div>

<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">Person</font></div>

<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">With</font></div>
</td>
<td valign="top" width="8%" style="BORDER-BOTTOM: black 2px solid">
<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="center"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">7.</font></div>
</td>
<td colspan="4" valign="top" width="70%" style="BORDER-BOTTOM: black 2px solid">
<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="justify"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">Sole Voting Power</font></div>

<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="justify"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; FONT-WEIGHT: bold; DISPLAY: inline">1,596,200 <font style="FONT-SIZE: 70%; VERTICAL-ALIGN: text-top; DISPLAY: inline">(1)</font></font></div>

<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="justify"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; FONT-WEIGHT: bold; DISPLAY: inline">341,444,304<font style="FONT-SIZE: 70%; VERTICAL-ALIGN: text-top; DISPLAY: inline">(2)</font></font></div>
</td>
</tr><tr>
<td valign="top" width="8%" style="BORDER-BOTTOM: black 2px solid">
<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="center"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">8.</font></div>
</td>
<td align="left" colspan="4" valign="top" width="70%" style="BORDER-BOTTOM: black 2px solid">
<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">Shared Voting Power</font></div>

<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; FONT-WEIGHT: bold; DISPLAY: inline">Not applicable</font></div>
</td>
</tr><tr>
<td valign="top" width="8%" style="BORDER-BOTTOM: black 2px solid">
<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="center"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">9.</font></div>
</td>
<td align="left" colspan="4" valign="top" width="70%" style="BORDER-BOTTOM: black 2px solid">
<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">Sole Dispositive Power</font></div>

<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; FONT-WEIGHT: bold; DISPLAY: inline">1,596,200 <font style="FONT-SIZE: 70%; VERTICAL-ALIGN: text-top; DISPLAY: inline">(1)</font></font></div>
</td>
</tr><tr>
<td valign="top" width="8%" style="BORDER-BOTTOM: black 2px solid">
<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="center"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">10.</font></div>
</td>
<td align="left" colspan="4" valign="top" width="70%" style="BORDER-BOTTOM: black 2px solid">
<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">Shared Dispositive Power</font></div>

<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; FONT-WEIGHT: bold; DISPLAY: inline">Not applicable</font></div>
</td>
</tr><tr>
<td valign="top" width="7%" style="BORDER-BOTTOM: black 2px solid">
<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="center"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">11.</font></div>
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<td colspan="6" valign="top" width="93%" style="BORDER-BOTTOM: black 2px solid">
<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="justify"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">&#160;Aggregate Amount Beneficially Owned by Each Reporting Person</font></div>

<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="justify"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; FONT-WEIGHT: bold; DISPLAY: inline">&#160;1,596,200 <font style="FONT-SIZE: 70%; VERTICAL-ALIGN: text-top; DISPLAY: inline">(1)</font></font></div>

<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="justify"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; FONT-WEIGHT: bold; DISPLAY: inline">&#160;341,444,304<font style="FONT-SIZE: 70%; VERTICAL-ALIGN: text-top; DISPLAY: inline">(2)</font></font></div>
</td>
</tr><tr>
<td valign="top" width="7%" style="BORDER-BOTTOM: black 2px solid">
<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="center"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">12.</font></div>
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<td colspan="3" valign="top" width="15%" style="BORDER-BOTTOM: black 2px solid">
<div><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">&#160; &#160;&#160; Check if the Aggregate Amount in Row (11) Excludes</font></div>

<div><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">&#160;&#160;&#160; &#160;Certain Shares (See Instructions)&#160;&#160;&#160;&#160;&#160;</font></div>
</td>
<td valign="top" width="15%" style="BORDER-BOTTOM: black 2px solid"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">&#160;</font></td>
<td valign="top" width="16%" style="BORDER-BOTTOM: black 2px solid"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">&#160;</font></td>
<td valign="top" width="16%" style="BORDER-BOTTOM: black 2px solid">
<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="justify"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">&#160;&#160;&#160;&#160;&#160;<font style="FONT-SIZE: 10pt; DISPLAY: inline"><font style="FONT-FAMILY: wingdings; DISPLAY: inline">o</font></font></font></div>
</td>
</tr><tr>
<td valign="top" width="7%" style="BORDER-BOTTOM: black 2px solid">
<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="center"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">13.</font></div>
</td>
<td colspan="6" valign="top" width="93%" style="BORDER-BOTTOM: black 2px solid">
<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="justify"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">&#160;Percent of Class Represented by Amount in Row (11)</font></div>

<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: -9pt" align="justify"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; FONT-WEIGHT: bold; DISPLAY: inline">&#160; &#160;&#160; 83.8%<font style="FONT-SIZE: 70%; VERTICAL-ALIGN: text-top; DISPLAY: inline">(3)</font></font></div>
</td>
</tr><tr>
<td valign="top" width="7%" style="BORDER-BOTTOM: black 2px solid">
<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="center"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">14.</font></div>
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<td colspan="6" valign="top" width="93%" style="BORDER-BOTTOM: black 2px solid">
<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="justify"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">&#160;Type of Reporting Person (See Instructions)</font></div>

<div style="MARGIN-LEFT: 9pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="justify"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; FONT-WEIGHT: bold; DISPLAY: inline">&#160;IN</font></div>
</td>
</tr></table>
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<div style="DISPLAY: block; TEXT-INDENT: 0pt"><br>
</div>

<div style="DISPLAY: block; TEXT-INDENT: 0pt"><br>
</div>

<div align="center">
<table border="0" cellpadding="0" cellspacing="0" id="hangingindent" width="100%" style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; FONT-SIZE: 10pt; FONT-FAMILY: times new roman">
<tr valign="top">
<td width="2%" style="WIDTH: 360pt">
<div style="MARGIN-LEFT: 0pt; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">(1)</font></div>
</td>
<td width="98%">
<div align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">Mr. Thomas Peterffy, through the ownership of his revocable trust of the voting membership interests in IBG Holdings LLC, beneficially owns 1,596,200 shares of Class A Common Stock, which were acquired on July 28, 2016. Beneficial ownership for this purpose includes the ability to vote the shares and the power to sell the shares. Mr. Thomas Peterffy has no economic interest in the shares of Class A Common Stock acquired on July 28, 2016. The economic interest in these shares accrues to those members of IBG Holdings LLC who redeemed their membership interests on July 28, 2016.</font></div>
</td>
</tr></table>
</div>

<div style="DISPLAY: block; TEXT-INDENT: 0pt"><br>
</div>

<div align="center">
<table border="0" cellpadding="0" cellspacing="0" id="hangingindent" width="100%" style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; FONT-SIZE: 10pt; FONT-FAMILY: times new roman">
<tr valign="top">
<td width="2%" style="WIDTH: 360pt">
<div style="MARGIN-LEFT: 0pt; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">(2)</font></div>
</td>
<td width="98%">
<div align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">Pursuant to the Amended and Restated Certificate of Incorporation of the issuer, Mr. Thomas Peterffy, through the ownership of his revocable trust of the voting membership interest in IBG Holdings LLC, beneficially owns all of the 100 outstanding shares of the issuer&#8217;s Class B Common Stock and accordingly is entitled to the number of votes equal to the number of IBG LLC membership interests held by IBG Holdings LLC at any given time.&#160;&#160;As of the date of this statement, IBG Holdings LLC holds 341,444,304 IBG LLC membership interests.</font></div>
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<div style="DISPLAY: block; TEXT-INDENT: 0pt"><br>
</div>

<div align="center">
<table border="0" cellpadding="0" cellspacing="0" id="hangingindent" width="100%" style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; FONT-SIZE: 10pt; FONT-FAMILY: times new roman">
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<td width="2%" style="WIDTH: 360pt">
<div style="MARGIN-LEFT: 0pt; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">(3)</font></div>
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<td width="98%">
<div align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">Mr. Thomas Peterffy, through the ownership of his revocable trust of the voting membership interests in IBG Holdings LLC, beneficially owns 1,596,200 shares of Class A Common Stock, which represents approximately&#160;2.4% of the outstanding shares of Class A Common Stock and approximately 0.4% of the voting power of the issuer.&#160;&#160;In addition, through his revocable trust&#8217;s ownership of the voting membership interests in IBG Holdings LLC, Mr. Thomas Peterffy beneficially owns all of the 100 outstanding shares of the issuer&#8217;s Class B Common Stock and accordingly holds approximately 83.4% of the voting power of the issuer through such ownership.&#160;&#160;In total, Mr. Thomas Peterffy holds approximately 83.8% of the voting power of the issuer through his revocable trust&#8217;s ownership of the voting membership interests in IBG Holdings LLC.</font></div>
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<br>
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<div style="TEXT-ALIGN: center; WIDTH: 100%"><font style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; DISPLAY: inline">3</font></div>

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<hr style="COLOR: black" noshade size="2">
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<div id="HDR">
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<br>
<div style="DISPLAY: block; TEXT-INDENT: 0pt">&#160;</div>

<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; DISPLAY: inline"><font style="FONT-WEIGHT: bold; DISPLAY: inline">Introductory Note:</font>&#160;&#160;This Amendment No. 4 to the Schedule 13D (this &#8220;Amendment&#8221;) filed by IBG Holdings LLC (&#8220;IBG Holdings&#8221;) and Thomas Peterffy (together with IBG Holdings, the &#8220;Reporting Persons&#8221;) relates to the acquisition of 1,596,200 shares of Class A Common Stock of Interactive Brokers Group, Inc. (the &#8220;Company&#8221;) by the Reporting Persons on July 28, 2016.&#160;&#160;This Amendment amends and supplements the Schedule 13D filed on May 17, 2007, which has been previously amended on November 18, 2013, October 24, 2014 and July 24, 2015 (the &#8220;Schedule 13D&#8221;) with respect to the Class A Common Stock of the Company.&#160;&#160;Except as specified in this Amendment, all previous Items are unchanged.&#160;&#160;Unless otherwise indicated herein, capitalized terms used but not defined in this Amendment shall have the same meanings herein as are ascribed to such terms in the Schedule 13D.</font></div>

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</div>

<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="justify">&#160;</div>

<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; FONT-WEIGHT: bold; DISPLAY: inline">Item 1. &#160;Security and Issuer</font></div>

<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="justify">&#160;</div>

<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; DISPLAY: inline">The third paragraph of Item 1 is hereby amended and restated to read as follows:</font></div>

<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="justify">&#160;</div>

<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; DISPLAY: inline"><font id="TAB1" style="MARGIN-LEFT: 36pt"></font>Pursuant to the Amended and Restated Certificate of Incorporation of the Company (the &#8220;<font style="TEXT-DECORATION: underline; DISPLAY: inline">Restated Charter</font>&#8221;), IBG Holdings, as the sole holder of the 100 outstanding shares of the Class B Common Stock, is entitled to the number of votes equal to the number of IBG LLC membership interests held by it at any given time. As of the date of this statement, IBG Holdings holds 341,444,304 IBG LLC membership interests, and, as a result, the Class B Common Stock held by IBG Holdings represents approximately 83.4% of the voting power of the Company.&#160; Mr. Thomas Peterffy, through his revocable trust&#8217;s ownership of the voting membership interests in IBG Holdings, beneficially owns all of the outstanding shares of the Class B Common Stock, which represent approximately 83.4% of the voting power of the Company.</font></div>

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</div>

<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="justify">&#160;</div>

<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; DISPLAY: inline">The following paragraph is hereby added to Item 1:</font></div>

<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="justify">&#160;</div>

<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; DISPLAY: inline"><font id="TAB1" style="MARGIN-LEFT: 36pt"></font>On July 28, 2016, consistent with the terms of that certain Exchange Agreement entered into by and among the Company, IBG Holdings and IBG&#160;LLC and the former members of IBG LLC, previously filed as exhibit 99.3 to this Schedule 13D on May 17, 2007, as amended by that certain amendment previously filed as exhibit 10.1 to the Form 8-K filed on June 12, 2012 and as further amended by that certain amendment filed as an exhibit 10.1 to the Form&#160;10-Q on November 9, 2015,&#160;&#160;IBG Holdings acquired 1,596,200 shares of Class A Common Stock from the Company in exchange for 1,596,200 membership interests owned by IBG Holdings in IBG LLC and certain tax benefit payments as described in the tax receivable agreement between IBG Holdings and the Company and previously filed as exhibit 10.3 to Form 10-Q on June 15, 2007 (the &#8220;<font style="TEXT-DECORATION: underline; DISPLAY: inline">TRA</font>&#8221;).&#160;&#160;Such 1,596,200 shares of Class A Common Stock represent approximately 2.4% of the outstanding shares of Class A Common Stock and approximately 0.4% of the voting power of the Company.&#160;&#160;Mr. Thomas Peterffy, through his revocable trust&#8217;s ownership of the voting membership interests in IBG Holdings, beneficially owns such 1,596,200 shares of Class A Common Stock, which represent approximately 0.4% of the voting power of the Company.</font></div>

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<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; FONT-WEIGHT: bold; DISPLAY: inline">Item 4. &#160;Purpose of Transaction</font></div>

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<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; DISPLAY: inline">Item 4 is hereby supplemented by adding the following paragraph:</font></div>

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<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; DISPLAY: inline"><font id="TAB1" style="MARGIN-LEFT: 36pt"></font>On July 28, 2016, IBG Holdings acquired 1,596,200 shares of Class A Common Stock in exchange for 1,596,200 membership interests owned by IBG Holdings in IBG LLC and certain tax benefit payments as described in the TRA.&#160;&#160;It is intended that the shares of Class A Common Stock acquired by IBG Holdings will be sold in open market transactions and the proceeds used to purchase the IBG Holdings&#8217; membership interests (or portions thereof) of certain of IBG Holdings&#8217; members who have elected to redeem their IBG Holdings membership interests (or portion thereof).&#160;&#160;The shares to be sold will be sold in open market transactions pursuant to Rule 10b5-1 trading plans, more fully described in &#8220;Item 6&#8212;Contracts, Arrangements, Understandings or Relationships With Respect to the Securities of the Issuer&#8221; of this report.</font></div>

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<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; FONT-WEIGHT: bold; DISPLAY: inline">Item 5. &#160;Interest in Securities of the Issuer</font></div>

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<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; DISPLAY: inline">Paragraph (b) of Item 5 is hereby amended and restated to read as follows:</font></div>

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<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; DISPLAY: inline"><font id="TAB1" style="MARGIN-LEFT: 36pt"></font>(b) Rows (7) through (10) of the cover pages to the Schedule 13D/A set forth (i) the number of shares of Class A Common Stock as to which there is sole power to vote or direct the vote or to dispose or direct the disposition and (ii) the number of shares of Class A Common Stock as to which there is shared power to vote or direct the vote or to dispose or direct the disposition.</font></div>

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<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; DISPLAY: inline">Paragraph (c) of Item 5 is hereby supplemented by adding the following paragraph:</font></div>

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<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; DISPLAY: inline"><font id="TAB1" style="MARGIN-LEFT: 36pt"></font>On July 28, 2016, IBG Holdings acquired 1,596,200 shares of Class A Common Stock in exchange for 1,596,200 membership interests owned by IBG Holdings in IBG LLC and certain tax benefit payments as described in the TRA.&#160;&#160;There were no other transactions in the Class A Common Stock by the Reporting Persons during the last sixty days.</font></div>

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<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; DISPLAY: inline">&#160;Paragraph (d) of Item 5 is hereby supplemented by adding the following paragraph:</font></div>

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<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; DISPLAY: inline"><font id="TAB1" style="MARGIN-LEFT: 36pt"></font>Messrs. Earl H. Nemser, Vice Chairman of the Board of the Company and Thomas A.J. Frank, Executive Vice President of the Company are among the members of IBG Holdings who have elected to redeem a portion of their IBG Holdings membership interests in connection with the July 28, 2016 transaction and therefore have an interest in the proceeds of sale of 50,000 and 1,000,000 shares, respectively, of the Class A Common Stock to be sold pursuant to the 2016 Plans (defined in Item 6). Certain current and former employees of the Company and its subsidiaries also elected the redemption of a portion of their membership interests in IBG Holdings and therefore have an interest in the balance of the shares to be sold under the Plans.<font style="FONT-WEIGHT: bold; DISPLAY: inline">&#160;</font>Neither Mr. Thomas Peterffy nor his affiliates have elected to redeem any of their IBG Holdings membership interests and therefore have no interest in the proceeds of sale of the shares of Class A Common Stock acquired by IBG Holdings on July 28, 2016.</font></div>

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<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; DISPLAY: inline">The first paragraph under subheading &#8220;Voting&#8221; of Item 6 is hereby amended and restated to read as follows:</font></div>

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<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 36pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; DISPLAY: inline">Pursuant to the Restated Charter, IBG Holdings, as the sole holder of the 100 outstanding shares of the Class B Common Stock, is entitled to the number of votes equal to the number of IBG LLC membership interests held by it at any given time. Except as otherwise provided by law and the Restated Charter, the Company&#8217;s shares of Class A Common Stock and Class B Common Stock vote together as a single class.&#160; As of the date of this statement, IBG Holdings holds 341,444,304 IBG LLC membership interests, and, as a result, the Class B Common Stock held by IBG Holdings represents approximately 83.4% of the voting power of the Company.&#160;Such percentage voting power is anticipated to decrease over time as a result of the exchange and redemption pursuant to the Exchange Agreement.&#160; Mr. Thomas Peterffy, through his revocable trust&#8217;s ownership of the voting membership interests in IBG Holdings, beneficially owns all of the outstanding shares of the Class B Common Stock which represent approximately 83.4% of the voting power of the Company.</font></div>

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<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 0pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; DISPLAY: inline">The following paragraphs are hereby added to Item 6 under the subheading &#8220;Voting&#8221;:</font></div>

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<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 36pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; DISPLAY: inline">On July 28, 2016, IBG Holdings acquired 1,596,200 shares of Class A Common Stock for sale for the benefit of certain of its members who elected to redeem a portion of their IBG Holdings membership interests. The shares of Class A Common Stock were acquired in exchange for 1,596,200 membership interests owned by IBG Holdings in IBG LLC and represent approximately 0.4% of the voting power of the Company.&#160;&#160;We anticipate a proportional reduction in the voting power of IBG Holdings as a result of these intended sales in open market transactions of such shares pursuant to the 2016 Plans. Mr. Thomas Peterffy, through his revocable trust&#8217;s ownership of the voting membership interests in IBG Holdings, beneficially owns 1,596,200 shares of Class A Common Stock, which represent approximately 0.4% of the voting power of the Company.</font></div>

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<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 36pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; DISPLAY: inline">In the aggregate, IBG Holdings holds approximately 83.8% of the voting power of the Company.&#160;&#160;Mr. Thomas Peterffy, through his revocable trust&#8217;s ownership of the voting membership interests in IBG Holdings, holds in the aggregate approximately 83.8% of the total voting power of the Company.</font></div>

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<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 36pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; DISPLAY: inline">On July 28, 2016, IBG Holdings entered into Rule 10b5-1 trading plans (the &#8220;<font style="TEXT-DECORATION: underline; DISPLAY: inline">2016 Plans</font>&#8221;) providing for the sale of 1,596,200 shares of Class A Common Stock acquired by IBG Holdings on July 28, 2016 in open market transactions. Under the terms of the 2016 Plans, IBG Holdings intends to sell the 1,596,200 shares of Class A common stock over time at prevailing market prices.&#160;&#160;The sales will occur until the earlier of the date on which all shares are sold, July 27, 2017 or the plans&#160;are terminated in accordance with their terms and Rule 10b5-1 of the Exchange Act and will be disclosed publicly in accordance with applicable securities laws, rules and regulations through appropriate filings with the Securities and Exchange Commission, as applicable. IBG Holdings and its members will have no control over the stock sales under the 2016 Plans.</font></div>

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<div style="MARGIN-LEFT: 0pt; DISPLAY: block; MARGIN-RIGHT: 0pt; TEXT-INDENT: 36pt" align="left"><font style="FONT-SIZE: 10pt; FONT-FAMILY: Times New Roman; DISPLAY: inline">After reasonable inquiry and to the best of its knowledge and belief, the undersigned certify that the information set forth in this Statement is true, complete and correct.</font></div>

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<td width="25%"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman">&#160;Dated: August 2, 2016&#160;</font></td>
<td width="25%"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman">&#160;IBG HOLDINGS LLC</font></td>
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<td width="25%" style="PADDING-BOTTOM: 2px"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman">&#160;By:</font></td>
<td width="25%" style="BORDER-BOTTOM: black 2px solid"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman">&#160;/s/ Thomas Peterffy</font></td>
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<td width="25%"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman">&#160;Name: Thomas Peterffy</font></td>
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<td width="25%"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman">&#160;Title: Managing Member</font></td>
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<td width="25%"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman">&#160;Dated: August 2, 2016</font></td>
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<td width="25%" style="BORDER-BOTTOM: black 2px solid"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman">&#160;/s/ Thomas Peterffy</font></td>
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<td width="25%"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman"><font style="FONT-SIZE: 10pt; FONT-FAMILY: times new roman; DISPLAY: inline">&#160;Thomas Peterffy</font></font></td>
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