<HTML>
<HEAD>
<TITLE>S-8</TITLE>
</HEAD>
<BODY bgcolor="#FFFFFF">
<!-- PAGEBREAK -->
<H5 align="left" style="page-break-before:always"><A HREF="#toc">Table of Contents</A></H5><P>
<DIV style="font-family: 'Times New Roman',Times,serif">




<DIV align="right" style="font-size: 10pt; margin-top: 12pt">Registration No.&nbsp;333-<U>&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;</U>
</DIV>


<DIV style="width: 100%; border-bottom: 2pt solid black; font-size: 1pt">&nbsp;</DIV>
<DIV style="width: 100%; border-bottom: 1pt solid black; font-size: 1pt">&nbsp;</DIV>




<DIV align="center" style="font-size: 14pt; margin-top: 12pt"><B>UNITED STATES SECURITIES AND EXCHANGE COMMISSION</B>
</DIV>

<DIV align="center" style="font-size: 12pt"><B>Washington, D.C. 20549</B>
</DIV>

<DIV align="center" style="font-size: 12pt"><B><DIV align="center"><DIV style="font-size: 3pt; margin-top: 6pt; width: 26%; border-bottom: 1px solid #000000">&nbsp;</DIV></DIV></B>
</DIV>

<DIV align="center" style="font-size: 18pt; margin-top: 6pt"><B>FORM S-8</B>
</DIV>

<DIV align="center" style="font-size: 12pt"><B>REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933</B></DIV>


<DIV align="center" style="font-size: 2pt"><DIV align="center"><DIV style="font-size: 3pt; margin-top: 6pt; width: 26%; border-bottom: 1px solid #000000">&nbsp;</DIV></DIV></DIV>


<DIV align="center" style="font-size: 24pt; margin-top: 12pt"><B>MARKETAXESS HOLDINGS INC.</B>
</DIV>

<DIV align="center" style="font-size: 10pt">(Exact Name of Registrant as Specified in Its Charter)</DIV>


<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="47%">&nbsp;</TD>
    <TD width="5%">&nbsp;</TD>
    <TD width="47%">&nbsp;</TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD align="center" valign="top"><B>Delaware</B>
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top"><B>52-2230784</B></TD>
</TR>
<TR valign="bottom">
    <TD align="center" valign="top">(State or Other Jurisdiction of
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">(I.R.S. Employer Identification No.)</TD>
</TR>
<TR valign="bottom">
    <TD align="center" valign="top">Incorporation or Organization)</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD align="center" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="center" valign="top"><B>140 Broadway,
42</B><SUP style="font-size: 85%; vertical-align: text-top"><B>nd</B></SUP>
<B>Floor</B></TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD align="center" valign="top"><B>New York, NY</B>
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top"><B>10005</B></TD>
</TR>
<TR valign="bottom">
    <TD align="center" valign="top">(Address of Principal Executive Offices)
</TD>
    <TD>&nbsp;</TD>
    <TD align="center" valign="top">(Zip Code)</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<DIV align="Center" style="font-size: 10pt; margin-top: 6pt"><DIV align="center"><DIV style="font-size: 3pt; margin-top: 16pt; width: 26%; border-top: 1px solid #000000">&nbsp;</DIV></DIV>

</DIV>

<DIV align="Center" style="font-size: 10pt; margin-top: 6pt"><B>MarketAxess Holdings Inc. 2004 Stock Incentive Plan<BR>
(Amended and Restated Effective April&nbsp;28, 2006)</B><BR>
(Full Title of the Plan)

</DIV>

<DIV align="Center" style="font-size: 10pt; margin-top: 6pt"><DIV align="center"><DIV style="font-size: 3pt; margin-top: 16pt; width: 26%; border-top: 1px solid #000000">&nbsp;</DIV></DIV>

</DIV>

<DIV align="Center" style="font-size: 10pt; margin-top: 6pt"><B>Richard M. McVey<BR>
Chief Executive Officer<BR>
MarketAxess Holdings Inc.<BR>
140 Broadway,
42</B><SUP style="font-size: 85%; vertical-align: text-top"><B>nd</b></SUP>
<B>Floor</B><BR>
<B>New York, NY 1005</B><BR>
(Name and Address of Agent for Service)

</DIV>

<DIV align="Center" style="font-size: 10pt; margin-top: 6pt"><B>(212)&nbsp;813-6000</B><BR>
(Telephone Number, Including Area Code, of Agent For Service)

</DIV>

<DIV align="Center" style="font-size: 10pt; margin-top: 6pt"><DIV align="center"><DIV style="font-size: 3pt; margin-top: 16pt; width: 26%; border-top: 1px solid #000000">&nbsp;</DIV></DIV>

</DIV>

<DIV align="Center" style="font-size: 10pt; margin-top: 6pt"><B><I>Copies to:</I></B>

</DIV>

<DIV align="Center" style="font-size: 10pt; margin-top: 6pt"><B>Adam J. Kansler, Esq.<BR>
Brian B. Margolis, Esq.<BR>
Proskauer Rose LLP<BR>
1585 Broadway<BR>
New York, NY 10036<BR>
(212)&nbsp;969-3000</B>

</DIV>

<DIV align="Center" style="font-size: 10pt; margin-top: 6pt"><DIV align="center"><DIV style="font-size: 3pt; margin-top: 16pt; width: 26%; border-top: 1px solid #000000">&nbsp;</DIV></DIV>

</DIV>

<DIV align="Center" style="font-size: 10pt; margin-top: 6pt"><B>CALCULATION OF REGISTRATION FEE</B>

</DIV>
<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom"  style="font-size: 1pt">
    <TD width="1%">&nbsp;</TD>
    <TD width="34%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD><!-- VRule -->
    <TD width="1%">&nbsp;</TD>
    <TD width="16%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD><!-- VRule -->
    <TD width="1%">&nbsp;</TD>
    <TD width="10%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD><!-- VRule -->
    <TD width="1%">&nbsp;</TD>
    <TD width="19%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD><!-- VRule -->
    <TD width="1%">&nbsp;</TD>
    <TD width="11%">&nbsp;</TD>

    <TD width="1%">&nbsp;</TD>
</TR><TR style="font-size: 1px" valign="bottom">
    <TD nowrap align="left" colspan="15" style="border-bottom: 3px double #000000">&nbsp;</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">    <TD width="1%">&nbsp;</TD>

    <TD>&nbsp;</TD>
    <TD style="border-right: 2px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD style="border-right: 2px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Proposed Maximum</B></TD>
    <TD style="border-right: 2px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Proposed Maximum</B></TD>
    <TD style="border-right: 2px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Amount</B></TD>
    <TD width="1%">&nbsp;</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">    <TD width="1%">&nbsp;</TD>

    <TD nowrap align="center"><B>Title Of Securities</B></TD>
    <TD style="border-right: 2px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Amount To Be</B></TD>
    <TD style="border-right: 2px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Offering Price</B></TD>
    <TD style="border-right: 2px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Aggregate</B></TD>
    <TD style="border-right: 2px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Of</B></TD>
    <TD width="1%">&nbsp;</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">    <TD width="1%">&nbsp;</TD>

    <TD nowrap align="center"><B>To Be Registered</B></TD>
    <TD style="border-right: 2px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Registered</B></TD>
    <TD style="border-right: 2px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Per Share</B></TD>
    <TD style="border-right: 2px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Offering Price</B></TD>
    <TD style="border-right: 2px solid #000000">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="center"><B>Registration Fee</B><SUP style="font-size: 85%; vertical-align: text-top"><B>(1)</B></SUP></TD>
    <TD width="1%">&nbsp;</TD>
</TR>

<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD width="1%" style="border-top: 2px solid #000000">&nbsp;</TD>
                    <TD style="border-top: 2px solid #000000"><DIV style="margin-left:15px; text-indent:-15px">Common Stock, par
value $0.003 per share</DIV></TD>
    <TD style="border-right: 2px solid #000000; border-top: 2px solid #000000">&nbsp;</TD>
    <TD style="border-top: 2px solid #000000">&nbsp;</TD>
    <TD align="center" valign="bottom" style="border-top: 2px solid #000000">6,670,000<SUP style="font-size: 85%; vertical-align: text-top"><B>(2)</B></SUP></TD>
    <TD style="border-right: 2px solid #000000; border-top: 2px solid #000000">&nbsp;</TD>
    <TD style="border-top: 2px solid #000000">&nbsp;</TD>

<TD align="center" valign="bottom" style="border-top: 2px solid #000000">$9.54<SUP style="font-size: 85%; vertical-align: text-top"><B>(3)</B></SUP></TD>
    <TD style="border-right: 2px solid #000000; border-top: 2px solid #000000">&nbsp;</TD>
    <TD style="border-top: 2px solid #000000">&nbsp;</TD>

<TD align="center" valign="bottom" style="border-top: 2px solid #000000">$63,631,800<SUP style="font-size: 85%; vertical-align: text-top"><B>(3)</B></SUP></TD>
    <TD style="border-right: 2px solid #000000; border-top: 2px solid #000000">&nbsp;</TD>
    <TD style="border-top: 2px solid #000000">&nbsp;</TD>

<TD align="center" valign="bottom" style="border-top: 2px solid #000000">$6,808.60</TD>
    <TD width="1%" style="border-top: 2px solid #000000">&nbsp;</TD>
</TR>
<TR style="font-size: 1px" valign="bottom">
    <TD nowrap align="left" colspan="15" style="border-top: 3px double #000000">&nbsp;</TD>
</TR>

<!-- End Table Body -->
</TABLE>
</DIV>


<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 6pt; width: 18%; border-top: 0px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="3%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left">(1)</TD>
    <TD>&nbsp;</TD>
    <TD>Pursuant to General Instruction E to Form S-8, a filing fee is only being paid with respect
to the registration of additional securities for the MarketAxess Holdings Inc. 2004 Stock
Incentive Plan (Amended and Restated Effective April&nbsp;28, 2006) (the &#147;Plan&#148;). A Registration
Statement on Form S-8 has previously been filed on November&nbsp;4, 2004 (Registration No.
333-120229) for the existing securities under the Plan.</TD>
</TR>

<TR style="font-size: 3pt"><TD>&nbsp;</TD></TR>

<TR valign="top">
    <TD nowrap align="left">(2)</TD>
    <TD>&nbsp;</TD>
    <TD>Represents the additional number of shares of common stock, par value $.003 per share
(&#147;Common Stock&#148;), that may be granted under the Plan.</TD>
</TR>

<TR style="font-size: 3pt"><TD>&nbsp;</TD></TR>

<TR valign="top">
    <TD nowrap align="left">(3)</TD>
    <TD>&nbsp;</TD>
    <TD>Calculated solely for purposes of this offering under Rules 457(c) and 457(h) of the
Securities Act of 1933, as amended, on the average of the high and low selling prices per
share of the Common Stock as reported on the NASDAQ National Market
on July&nbsp;27, 2006.</TD>
</TR>

</TABLE>



<DIV style="width: 100%; border-bottom: 1pt solid black; margin-top: 10pt; font-size: 1pt">&nbsp;</DIV>
<DIV style="width: 100%; border-bottom: 2pt solid black; font-size: 1pt">&nbsp;</DIV>





<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<!-- TOC -->
<A name="toc"><DIV align="CENTER" style="page-break-before:always"><U><B>TABLE OF CONTENTS</B></U></DIV></A>

<P><CENTER>
<TABLE border="0" width="90%" cellpadding="0" cellspacing="0">
<TR>
	<TD width="3%"></TD>
	<TD width="3%"></TD>
	<TD width="3%"></TD>
	<TD width="3%"></TD>
	<TD width="3%"></TD>
	<TD width="3%"></TD>
	<TD width="3%"></TD>
	<TD width="3%"></TD>
	<TD width="76%"></TD>
</TR>
<TR><TD colspan="9"><A HREF="#000">PART II</A></TD></TR>
<TR><TD></TD><TD colspan="8"><A HREF="#001">Item&nbsp;3. Incorporation of Documents by Reference</A></TD></TR>
<TR><TD></TD><TD colspan="8"><A HREF="#002">Item&nbsp;8. Exhibits</A></TD></TR>
<TR><TD colspan="9"><A HREF="#003">SIGNATURES</A></TD></TR>
<TR><TD colspan="9"><A HREF="#004">EXHIBIT INDEX</A></TD></TR>
<TR><TD colspan="9"><A HREF="y23605exv5w1.htm">EX-5.1: OPINION OF PROSKAUER ROSE LLP</A></TD></TR>
<TR><TD colspan="9"><A HREF="y23605exv23w2.htm">EX-23.2: CONSENT OF PRICEWATERHOUSECOOPERS LLP</A></TD></TR>
</TABLE>
</CENTER>
<!-- /TOC -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always"><A HREF="#toc">Table of Contents</A></H5><P>





<DIV align="center" style="font-size: 10pt; margin-top: 18pt"><B>Explanatory
Note</B>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;This Registration Statement is filed pursuant to General Instruction E to Form S-8. The
contents of the Registration Statement on Form S-8 (Registration No.&nbsp;333-120229) are incorporated
herein by reference and made a part hereof.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;<U>Registration of Additional Shares of Common Stock Under the Plan</U>. The aggregate
number of shares of Common Stock that may be subject to awards under the Plan is increased from
3,084,802 to 9,754,802.
</DIV>



<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always"><A HREF="#toc">Table of Contents</A></H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">



<!-- link1 "PART II " -->
<DIV align="left"><A NAME="000"></A></DIV>

<DIV align="center" style="font-size: 10pt; margin-top: 18pt"><B>PART II</B>
</DIV>


<DIV align="Center" style="font-size: 10pt; margin-top: 6pt"><B>INFORMATION REQUIRED IN THE REGISTRATION STATEMENT</B>

</DIV>
<!-- link2 "Item&nbsp;3. Incorporation of Documents by Reference" -->
<DIV align="left"><A NAME="001"></A></DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>Item&nbsp;3. Incorporation of Documents by Reference.</B>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;The contents of the Registration Statement on Form S-8 previously filed with the Securities
and Exchange Commission (the &#147;Commission&#148;) on November&nbsp;4, 2004 (Registration No.&nbsp;333-120229) by
MarketAxess Holdings Inc., a Delaware corporation (the &#147;Corporation&#148; or the &#147;Registrant&#148;), are
incorporated herein by reference. In addition, the Registrant hereby incorporates by reference
into this Registration Statement the following documents previously filed with the Commission:
</DIV>


<DIV style="margin-top: 6pt">
<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">

<TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" nowrap align="left">(a)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>the Registrant&#146;s Annual Report on Form 10-K for the fiscal year ended December&nbsp;31, 2005,
filed with the Commission on March&nbsp;14, 2006;</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" nowrap align="left">(b)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>the Registrant&#146;s Quarterly Report on Form 10-Q for the fiscal quarter ended March&nbsp;31, 2006,
filed with the Commission on May&nbsp;10, 2006;</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" nowrap align="left">(c)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>the Registrant&#146;s Reports on Form 8-K filed on February&nbsp;2, 2006, April&nbsp;5, 2006 and July&nbsp;12,
2006; and</TD>
</TR>

<TR>
    <TD style="font-size: 6pt">&nbsp;</TD>
</TR><TR valign="top" style="font-size: 10pt; color: #000000; background: transparent">
    <TD width="3%" nowrap align="left">(d)</TD>
    <TD width="1%">&nbsp;</TD>
    <TD>the Registrant&#146;s Registration Statement No.&nbsp;000-50670 on Form 8-A filed with the Commission
on April&nbsp;1, 2004 pursuant to Section 12(g) of the Securities Exchange Act of 1934 (the
&#147;Exchange Act&#148;), in which there is described the terms, rights, and provisions applicable to
the Registrant&#146;s common stock, par value $0.003 per share (the &#147;Common Stock&#148;).</TD>
</TR>

</TABLE>
</DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;All documents filed by the Registrant pursuant to Sections&nbsp;13(a), 13(c), 14 and 15(d) of the
Exchange Act, subsequent to the effective date of this Registration Statement, prior to the filing
of a post-effective amendment to this Registration Statement indicating that all securities offered
hereby have been sold or deregistering all securities then remaining unsold, shall be deemed to be
incorporated by reference herein and to be part hereof from the date of filing of such documents.
We are not, however, incorporating by reference any documents or portions thereof, whether
specifically listed above or filed in the future, that are not deemed &#147;filed&#148; with the SEC,
including our compensation committee report and performance graph (included in our Definitive Proxy
Statement), or any information furnished pursuant to Items 2.02 or 7.01 of Form 8-K, or certain
exhibits furnished pursuant to Item&nbsp;9.01 of Form 8-K. Any statement contained in a document
incorporated or deemed to be incorporated by reference herein shall be deemed to be modified or
superseded for purposes of this Registration Statement to the extent that a statement contained
herein or in any other subsequently filed document which also is or is deemed to be incorporated by
reference herein modifies or replaces such statement. Any statement contained in a document that
is deemed to be incorporated by reference or deemed to be part of this Registration Statement after
the most recent effective date may modify or replace existing statements contained in this
Registration Statement. Any such statement so modified or superseded shall not be deemed to
constitute a part of this Registration Statement, except as so modified or superseded.
</DIV>

<!-- link2 "Item&nbsp;8. Exhibits" -->
<DIV align="left"><A NAME="002"></A></DIV>

<DIV align="left" style="font-size: 10pt; margin-top: 12pt"><B>Item&nbsp;8. Exhibits.</B>
</DIV>

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="4%">&nbsp;</TD>
    <TD width="4%">&nbsp;</TD>
    <TD width="90%">&nbsp;</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD nowrap align="left" style="border-bottom: 1px solid #000000"><B>Exhibit No.</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="left" style="border-bottom: 1px solid #000000"><B>Description</B></TD>
</TR>

<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">5.1*
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Opinion of Proskauer Rose LLP.</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">23.1*
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Consent of Proskauer Rose LLP (included in the opinion filed as Exhibit&nbsp;5.1).</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">23.2*
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Consent of PricewaterhouseCoopers LLP.</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">24.1*
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Power of Attorney (included on signature page).</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">99.1
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">MarketAxess Holdings Inc. 2004 Stock Incentive Plan (Amended and Restated
Effective April&nbsp;28, 2006) (incorporated by reference to Appendix&nbsp;A to the
Proxy Statement of the Registrant, filed with the Commission on May&nbsp;1, 2006)</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>



<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="3%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left">*</TD>
    <TD>&nbsp;</TD>
    <TD>Filed Herewith</TD>
</TR>

</TABLE>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always"><A HREF="#toc">Table of Contents</A></H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">





<!-- link1 "SIGNATURES" -->
<DIV align="left"><A NAME="003"></A></DIV>

<DIV align="center" style="font-size: 10pt; margin-top: 18pt"><B>SIGNATURES</B>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Pursuant to the requirements of the Securities Act of 1933, the Registrant certifies that it
has reasonable grounds to believe that it meets all of the requirements for filing on Form S-8 and
has duly caused this Registration Statement to be signed on its behalf by the undersigned,
thereunto duly authorized, in the city of New York, state of New York
on this 28th day of July,
2006.
</DIV>

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="48%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="35%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="12%">&nbsp;</TD>
</TR>
<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD colspan="3" valign="top" align="left"><B>MARKETAXESS HOLDINGS INC.</B></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">By:
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">/s/ <FONT style="font-variant: SMALL-CAPS">Richard M. McVey</FONT>
<DIV style="font-size: 1pt; border-top: 1px solid #000000">&nbsp;</DIV>
Richard M. McVey<BR>
President, Chief Executive Officer and
Chairman of the Board of Directors
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<DIV align="center" style="font-size: 10pt; margin-top: 18pt"><B>POWER OF ATTORNEY</B>
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;KNOW ALL PERSONS BY THESE PRESENTS that each person whose signature appears below hereby
constitutes and appoints Richard M. McVey, Charles R. Hood and James N.B. Rucker, or any of them
individually, such person&#146;s true and lawful attorneys-in-fact and agents, with full power of
substitution and resubstitution, for and in such person&#146;s name, place and stead, in the capacities
indicated below, to sign this Registration Statement on Form S-8 of MarketAxess Holdings Inc. and
any and all amendments (including post-effective amendments) thereto, and to file or cause to be
filed the same, with all exhibits thereto, and other documents in connection therewith, with the
Securities and Exchange Commission, granting unto said attorneys-in-fact and agents, and each of
them, full power and authority to do and perform each and every act and thing requisite and
necessary to be done in connection therewith, as fully to all intents and purposes as such person
might, or could, do in person, hereby ratifying and confirming all that said attorneys-in-fact and
agents, and each of them, or his or her substitute or substitutes, may lawfully do or cause to be
done by virtue hereof.
</DIV>


<DIV align="left" style="font-size: 10pt; margin-top: 6pt">&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;Pursuant to the requirements of the Securities Act of 1933, this Registration Statement has
been signed on July 28, 2006 by the following persons in the capacities indicated.
</DIV>
<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="10%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="35%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="15%">&nbsp;</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD nowrap align="center" style="border-bottom: 1px solid #000000"><B>Signature</B></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="left" style="border-bottom: 1px solid #000000"><B>Title</B></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR>

<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">/s/ <FONT style="font-variant: SMALL-CAPS">Richard M. McVey</FONT>
<DIV style="font-size: 1pt; border-top: 1px solid #000000">&nbsp;</DIV>
Richard M. McVey
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top" nowrap>President, Chief Executive Officer and
Chairman of the <BR>Board of Directors
(Principal Executive Officer)
</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">/s/ <FONT style="font-variant: SMALL-CAPS">James N. B. Rucker</FONT>
<DIV style="font-size: 1pt; border-top: 1px solid #000000">&nbsp;</DIV>
James N.B. Rucker
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Chief Financial Officer (Principal
Financial and Accounting Officer)</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">/s/ <FONT style="font-variant: SMALL-CAPS">Stephen P. Casper</FONT>
<DIV style="font-size: 1pt; border-top: 1px solid #000000">&nbsp;</DIV>
Stephen P. Casper
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Director</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">/s/ <FONT style="font-variant: SMALL-CAPS">David G. Gomach</FONT>
<DIV style="font-size: 1pt; border-top: 1px solid #000000">&nbsp;</DIV>
David G. Gomach
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Director</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always"><A HREF="#toc">Table of Contents</A></H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="30%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="10%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="35%">&nbsp;</TD>
    <TD width="1%">&nbsp;</TD>
    <TD width="15%">&nbsp;</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD nowrap align="center" style="border-bottom: 1px solid #000000"><B>Signature</B></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="left" style="border-bottom: 1px solid #000000"><B>Title</B></TD>
    <TD>&nbsp;</TD>
    <TD>&nbsp;</TD>
</TR>

<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">/s/ <FONT style="font-variant: SMALL-CAPS">Carlos M. Hernandez</FONT>
<DIV style="font-size: 1pt; border-top: 1px solid #000000">&nbsp;</DIV>
Carlos M. Hernandez
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Director</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">/s/ <FONT style="font-variant: SMALL-CAPS">Ronald M. Hersch</FONT>
<DIV style="font-size: 1pt; border-top: 1px solid #000000">&nbsp;</DIV>
Ronald M. Hersch
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Director</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">/s/ <FONT style="font-variant: SMALL-CAPS">Wayne D. Lyski</FONT>
<DIV style="font-size: 1pt; border-top: 1px solid #000000">&nbsp;</DIV>
Wayne D. Lyski
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Director</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">/s/ <FONT style="font-variant: SMALL-CAPS">Jerome S. Markowitz</FONT>
<DIV style="font-size: 1pt; border-top: 1px solid #000000">&nbsp;</DIV>
Jerome S. Markowitz
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Director</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">/s/ <FONT style="font-variant: SMALL-CAPS">Nicolas S. Rohatyn</FONT>
<DIV style="font-size: 1pt; border-top: 1px solid #000000">&nbsp;</DIV>
Nicolas S. Rohatyn
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Director</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">/s/ <FONT style="font-variant: SMALL-CAPS">John Steinhardt</FONT>
<DIV style="font-size: 1pt; border-top: 1px solid #000000">&nbsp;</DIV>
John Steinhardt
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Director</TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>



<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

<!-- PAGEBREAK -->
<P><HR noshade><P>
<H5 align="left" style="page-break-before:always"><A HREF="#toc">Table of Contents</A></H5><P>

<DIV style="font-family: 'Times New Roman',Times,serif">



<!-- link1 "EXHIBIT INDEX" -->
<DIV align="left"><A NAME="004"></A></DIV>

<DIV align="center" style="font-size: 10pt; margin-top: 18pt"><B>EXHIBIT INDEX</B>
</DIV>

<DIV align="center">
<TABLE style="font-size: 10pt" cellspacing="0" border="0" cellpadding="0" width="100%">
<!-- Begin Table Head -->
<TR valign="bottom">
    <TD width="4%">&nbsp;</TD>
    <TD width="4%">&nbsp;</TD>
    <TD width="90%">&nbsp;</TD>
</TR>
<TR style="font-size: 8pt" valign="bottom">
    <TD nowrap align="left" style="border-bottom: 1px solid #000000"><B>Exhibit No.</B></TD>
    <TD>&nbsp;</TD>
    <TD nowrap align="left" style="border-bottom: 1px solid #000000"><B>Description</B></TD>
</TR>

<!-- End Table Head -->
<!-- Begin Table Body -->
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">5.1*
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Opinion of Proskauer Rose LLP.</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">23.1*
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Consent of Proskauer Rose LLP (included in the opinion filed as Exhibit&nbsp;5.1).</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">23.2*
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Consent of PricewaterhouseCoopers LLP.</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">24.1*
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">Power of Attorney (included on signature page).</TD>
</TR>
<TR valign="bottom"><!-- Blank Space -->
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">&nbsp;</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">&nbsp;</TD>
</TR>
<TR valign="bottom">
    <TD valign="top"><DIV style="margin-left:0px; text-indent:-0px">99.1
</DIV></TD>
    <TD>&nbsp;</TD>
    <TD align="left" valign="top">MarketAxess Holdings Inc. 2004 Stock Incentive Plan (Amended and Restated
Effective April&nbsp;28, 2006) (incorporated by reference to Appendix&nbsp;A to the
Proxy Statement of the Registrant, filed with the Commission on May&nbsp;1, 2006)</TD>
</TR>
<!-- End Table Body -->
</TABLE>
</DIV>



<DIV align="left">
<DIV style="font-size: 3pt; margin-top: 16pt; width: 18%; border-top: 1px solid #000000">&nbsp;</DIV>
</DIV>

<TABLE width="100%" border="0" cellpadding="0" cellspacing="0" style="font-size: 10pt">
<TR>
    <TD width="3%"></TD>
    <TD width="1%"></TD>
    <TD width="96"></TD>
</TR>

<TR valign="top">
    <TD nowrap align="left">*</TD>
    <TD>&nbsp;</TD>
    <TD>Filed Herewith</TD>
</TR>

</TABLE>


<P align="center" style="font-size: 10pt">&nbsp;
</DIV>

</BODY>
</HTML>
[{"type": "S-8", "sequence": "1", "filename": "y23605sv8.htm", "description": "FORM S-8", "secsgml_size_bytes": 39946}]
{"company-data": {"conformed-name": "MARKETAXESS HOLDINGS INC", "cik": "0001278021", "assigned-sic": "6211", "irs-number": "522230784"}, "filing-values": {"form-type": "S-8", "act": "33", "file-number": "333-136101", "film-number": "06986806"}, "business-address": {"street1": "140 BROADWAY 42ND FLOOR", "city": "NEW YORK", "state": "NY", "zip": "10005", "phone": "212-831-6000"}, "mail-address": {"street1": "140 BROADWAY 42ND FLOOR", "city": "NEW YORK", "state": "NY", "zip": "10005"}, "former-company": {"former-conformed-name": "MARKETAXESS HOLDING INC", "date-changed": "20040129"}}
S-8
Table of Contents
Registration No. 333-
UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549
FORM S-8
REGISTRATION STATEMENT UNDER THE SECURITIES ACT OF 1933
MARKETAXESS HOLDINGS INC.
(Exact Name of Registrant as Specified in Its Charter)
Delaware
52-2230784
(State or Other Jurisdiction of
(I.R.S. Employer Identification No.)
Incorporation or Organization)
140 Broadway,
42
nd
Floor
New York, NY
10005
(Address of Principal Executive Offices)
(Zip Code)
MarketAxess Holdings Inc. 2004 Stock Incentive Plan
(Amended and Restated Effective April 28, 2006)
(Full Title of the Plan)
Richard M. McVey
Chief Executive Officer
MarketAxess Holdings Inc.
140 Broadway,
42
nd
Floor
New York, NY 1005
(Name and Address of Agent for Service)
(212) 813-6000
(Telephone Number, Including Area Code, of Agent For Service)
Copies to:
Adam J. Kansler, Esq.
Brian B. Margolis, Esq.
Proskauer Rose LLP
1585 Broadway
New York, NY 10036
(212) 969-3000
CALCULATION OF REGISTRATION FEE
Proposed Maximum
Proposed Maximum
Amount
Title Of Securities
Amount To Be
Offering Price
Aggregate
Of
To Be Registered
Registered
Per Share
Offering Price
Registration Fee
(1)
Common Stock, par
value $0.003 per share
6,670,000
(2)
$9.54
(3)
$63,631,800
(3)
$6,808.60
(1)
Pursuant to General Instruction E to Form S-8, a filing fee is only being paid with respect
to the registration of additional securities for the MarketAxess Holdings Inc. 2004 Stock
Incentive Plan (Amended and Restated Effective April 28, 2006) (the "Plan"). A Registration
Statement on Form S-8 has previously been filed on November 4, 2004 (Registration No.
333-120229) for the existing securities under the Plan.
(2)
Represents the additional number of shares of common stock, par value $.003 per share
("Common Stock"), that may be granted under the Plan.
(3)
Calculated solely for purposes of this offering under Rules 457(c) and 457(h) of the
Securities Act of 1933, as amended, on the average of the high and low selling prices per
share of the Common Stock as reported on the NASDAQ National Market
on July 27, 2006.
TABLE OF CONTENTS
PART II
Item 3. Incorporation of Documents by Reference
Item 8. Exhibits
SIGNATURES
EXHIBIT INDEX
EX-5.1: OPINION OF PROSKAUER ROSE LLP
EX-23.2: CONSENT OF PRICEWATERHOUSECOOPERS LLP
Table of Contents
Explanatory
Note
This Registration Statement is filed pursuant to General Instruction E to Form S-8. The
contents of the Registration Statement on Form S-8 (Registration No. 333-120229) are incorporated
herein by reference and made a part hereof.
Registration of Additional Shares of Common Stock Under the Plan
. The aggregate
number of shares of Common Stock that may be subject to awards under the Plan is increased from
3,084,802 to 9,754,802.
Table of Contents
PART II
INFORMATION REQUIRED IN THE REGISTRATION STATEMENT
Item 3. Incorporation of Documents by Reference.
The contents of the Registration Statement on Form S-8 previously filed with the Securities
and Exchange Commission (the "Commission") on November 4, 2004 (Registration No. 333-120229) by
MarketAxess Holdings Inc., a Delaware corporation (the "Corporation" or the "Registrant"), are
incorporated herein by reference. In addition, the Registrant hereby incorporates by reference
into this Registration Statement the following documents previously filed with the Commission:
(a)
the Registrant's Annual Report on Form 10-K for the fiscal year ended December 31, 2005,
filed with the Commission on March 14, 2006;
(b)
the Registrant's Quarterly Report on Form 10-Q for the fiscal quarter ended March 31, 2006,
filed with the Commission on May 10, 2006;
(c)
the Registrant's Reports on Form 8-K filed on February 2, 2006, April 5, 2006 and July 12,
2006; and
(d)
the Registrant's Registration Statement No. 000-50670 on Form 8-A filed with the Commission
on April 1, 2004 pursuant to Section 12(g) of the Securities Exchange Act of 1934 (the
"Exchange Act"), in which there is described the terms, rights, and provisions applicable to
the Registrant's common stock, par value $0.003 per share (the "Common Stock").
All documents filed by the Registrant pursuant to Sections 13(a), 13(c), 14 and 15(d) of the
Exchange Act, subsequent to the effective date of this Registration Statement, prior to the filing
of a post-effective amendment to this Registration Statement indicating that all securities offered
hereby have been sold or deregistering all securities then remaining unsold, shall be deemed to be
incorporated by reference herein and to be part hereof from the date of filing of such documents.
We are not, however, incorporating by reference any documents or portions thereof, whether
specifically listed above or filed in the future, that are not deemed "filed" with the SEC,
including our compensation committee report and performance graph (included in our Definitive Proxy
Statement), or any information furnished pursuant to Items 2.02 or 7.01 of Form 8-K, or certain
exhibits furnished pursuant to Item 9.01 of Form 8-K. Any statement contained in a document
incorporated or deemed to be incorporated by reference herein shall be deemed to be modified or
superseded for purposes of this Registration Statement to the extent that a statement contained
herein or in any other subsequently filed document which also is or is deemed to be incorporated by
reference herein modifies or replaces such statement. Any statement contained in a document that
is deemed to be incorporated by reference or deemed to be part of this Registration Statement after
the most recent effective date may modify or replace existing statements contained in this
Registration Statement. Any such statement so modified or superseded shall not be deemed to
constitute a part of this Registration Statement, except as so modified or superseded.
Item 8. Exhibits.
Exhibit No.
Description
5.1*
Opinion of Proskauer Rose LLP.
23.1*
Consent of Proskauer Rose LLP (included in the opinion filed as Exhibit 5.1).
23.2*
Consent of PricewaterhouseCoopers LLP.
24.1*
Power of Attorney (included on signature page).
99.1
MarketAxess Holdings Inc. 2004 Stock Incentive Plan (Amended and Restated
Effective April 28, 2006) (incorporated by reference to Appendix A to the
Proxy Statement of the Registrant, filed with the Commission on May 1, 2006)
*
Filed Herewith
Table of Contents
SIGNATURES
Pursuant to the requirements of the Securities Act of 1933, the Registrant certifies that it
has reasonable grounds to believe that it meets all of the requirements for filing on Form S-8 and
has duly caused this Registration Statement to be signed on its behalf by the undersigned,
thereunto duly authorized, in the city of New York, state of New York
on this 28th day of July,
2006.
MARKETAXESS HOLDINGS INC.
By:
/s/
Richard M. McVey
Richard M. McVey
President, Chief Executive Officer and
Chairman of the Board of Directors
POWER OF ATTORNEY
KNOW ALL PERSONS BY THESE PRESENTS that each person whose signature appears below hereby
constitutes and appoints Richard M. McVey, Charles R. Hood and James N.B. Rucker, or any of them
individually, such person's true and lawful attorneys-in-fact and agents, with full power of
substitution and resubstitution, for and in such person's name, place and stead, in the capacities
indicated below, to sign this Registration Statement on Form S-8 of MarketAxess Holdings Inc. and
any and all amendments (including post-effective amendments) thereto, and to file or cause to be
filed the same, with all exhibits thereto, and other documents in connection therewith, with the
Securities and Exchange Commission, granting unto said attorneys-in-fact and agents, and each of
them, full power and authority to do and perform each and every act and thing requisite and
necessary to be done in connection therewith, as fully to all intents and purposes as such person
might, or could, do in person, hereby ratifying and confirming all that said attorneys-in-fact and
agents, and each of them, or his or her substitute or substitutes, may lawfully do or cause to be
done by virtue hereof.
Pursuant to the requirements of the Securities Act of 1933, this Registration Statement has
been signed on July 28, 2006 by the following persons in the capacities indicated.
Signature
Title
/s/
Richard M. McVey
Richard M. McVey
President, Chief Executive Officer and
Chairman of the
Board of Directors
(Principal Executive Officer)
/s/
James N. B. Rucker
James N.B. Rucker
Chief Financial Officer (Principal
Financial and Accounting Officer)
/s/
Stephen P. Casper
Stephen P. Casper
Director
/s/
David G. Gomach
David G. Gomach
Director
Table of Contents
Signature
Title
/s/
Carlos M. Hernandez
Carlos M. Hernandez
Director
/s/
Ronald M. Hersch
Ronald M. Hersch
Director
/s/
Wayne D. Lyski
Wayne D. Lyski
Director
/s/
Jerome S. Markowitz
Jerome S. Markowitz
Director
/s/
Nicolas S. Rohatyn
Nicolas S. Rohatyn
Director
/s/
John Steinhardt
John Steinhardt
Director
Table of Contents
EXHIBIT INDEX
Exhibit No.
Description
5.1*
Opinion of Proskauer Rose LLP.
23.1*
Consent of Proskauer Rose LLP (included in the opinion filed as Exhibit 5.1).
23.2*
Consent of PricewaterhouseCoopers LLP.
24.1*
Power of Attorney (included on signature page).
99.1
MarketAxess Holdings Inc. 2004 Stock Incentive Plan (Amended and Restated
Effective April 28, 2006) (incorporated by reference to Appendix A to the
Proxy Statement of the Registrant, filed with the Commission on May 1, 2006)
*
Filed Herewith