<SUBMISSION>
<ACCESSION-NUMBER>0001193125-08-198525
<TYPE>8-K
<PUBLIC-DOCUMENT-COUNT>2
<PERIOD>20080919
<ITEMS>8.01
<ITEMS>9.01
<FILING-DATE>20080919
<DATE-OF-FILING-DATE-CHANGE>20080919
<FILER>
<COMPANY-DATA>
<CONFORMED-NAME>SEI INVESTMENTS CO
<CIK>0000350894
<ASSIGNED-SIC>6211
<IRS-NUMBER>231707341
<STATE-OF-INCORPORATION>PA
<FISCAL-YEAR-END>1231
</COMPANY-DATA>
<FILING-VALUES>
<FORM-TYPE>8-K
<ACT>34
<FILE-NUMBER>000-10200
<FILM-NUMBER>081080044
</FILING-VALUES>
<BUSINESS-ADDRESS>
<STREET1>1 FREEDOM VALLEY DRIVE
<CITY>OAKS
<STATE>PA
<ZIP>19456-1100
<PHONE>6106761000
</BUSINESS-ADDRESS>
<MAIL-ADDRESS>
<STREET1>1 FREEDOM VALLEY DRIVE
<CITY>OAKS
<STATE>PA
<ZIP>19456-1100
</MAIL-ADDRESS>
<FORMER-COMPANY>
<FORMER-CONFORMED-NAME>SEI INVESTMENT CO
<DATE-CHANGED>20040806
</FORMER-COMPANY>
<FORMER-COMPANY>
<FORMER-CONFORMED-NAME>SEI CORP
<DATE-CHANGED>19920703
</FORMER-COMPANY>
</FILER>
<DOCUMENT>
<TYPE>8-K
<SEQUENCE>1
<FILENAME>d8k.htm
<DESCRIPTION>FORM 8-K
<TEXT>
<HTML><HEAD>
<TITLE>Form 8-K</TITLE>
</HEAD>
 <BODY BGCOLOR="WHITE">
 <P STYLE="line-height:0px;margin-top:0px;margin-bottom:0px;border-bottom:0.5pt solid #000000">&nbsp;</P> <P
STYLE="line-height:3px;margin-top:0px;margin-bottom:2px;border-bottom:0.5pt solid #000000">&nbsp;</P> <P STYLE="margin-top:3px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="5"><B>UNITED STATES </B></FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="5"><B>SECURITIES AND EXCHANGE COMMISSION </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman"
SIZE="3"><B>Washington, D.C. 20549 </B></FONT></P> <P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P><center> <P
STYLE="line-height:6px;margin-top:0px;margin-bottom:2px;border-bottom:1pt solid #000000;width:21%">&nbsp;</P></center> <P STYLE="margin-top:12px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="5"><B>FORM 8-K </B></FONT></P> <P
STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P><center> <P STYLE="line-height:6px;margin-top:0px;margin-bottom:2px;border-bottom:1pt solid #000000;width:21%">&nbsp;</P></center> <P STYLE="margin-top:12px;margin-bottom:0px"
ALIGN="center"><FONT FACE="Times New Roman" SIZE="3"><B>CURRENT REPORT </B></FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="3"><B>Pursuant to Section&nbsp;13 or 15(d) of the Securities
Exchange Act of 1934 </B></FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>September&nbsp;19, 2008 </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT
FACE="Times New Roman" SIZE="2"><B>Date of report (Date of earliest event reported) </B></FONT></P> <P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P><center> <P
STYLE="line-height:6px;margin-top:0px;margin-bottom:2px;border-bottom:1pt solid #000000;width:21%">&nbsp;</P></center> <P STYLE="margin-top:12px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="6"><B>SEI Investments Company </B>
</FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>(Exact name of registrant as specified in its charter) </B></FONT></P> <P
STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P><center> <P STYLE="line-height:6px;margin-top:0px;margin-bottom:2px;border-bottom:1pt solid #000000;width:21%">&nbsp;</P></center> <P
STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" ALIGN="center">

<TR>
<TD WIDTH="34%"></TD>
<TD VALIGN="bottom" WIDTH="1%"></TD>
<TD WIDTH="32%"></TD>
<TD VALIGN="bottom" WIDTH="1%"></TD>
<TD WIDTH="32%"></TD></TR>
<TR>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>Pennsylvania</B></FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>0-10200</B></FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>23-1707341</B></FONT></TD></TR>
<TR>
<TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>(State or other jurisdiction</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px" ALIGN="center"><FONT
FACE="Times New Roman" SIZE="1"><B>of incorporation)</B></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>(Commission File No.)</B></FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top" ALIGN="center"> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>(I.R.S. Employer</B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:1px" ALIGN="center"><FONT
FACE="Times New Roman" SIZE="1"><B>Identification No.)</B></FONT></P></TD></TR>
</TABLE> <P STYLE="margin-top:12px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>1 Freedom Valley Drive </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"
ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>Oaks, Pennsylvania 19456 </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>(Address of principal executive offices) (Zip Code)
</B></FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>(610) 676-1000 </B></FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman"
SIZE="1"><B>(Registrants&#146; telephone number, including area code) </B></FONT></P> <P STYLE="margin-top:12px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>Not applicable </B></FONT></P> <P
STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="1"><B>(Former name or former address, if changed since last report) </B></FONT></P> <P
STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P><center> <P STYLE="line-height:6px;margin-top:0px;margin-bottom:2px;border-bottom:1pt solid #000000;width:21%">&nbsp;</P></center> <P STYLE="margin-top:12px;margin-bottom:0px"><FONT
FACE="Times New Roman" SIZE="2">Check the appropriate box below if the Form 8-K filing is intended to simultaneously satisfy the filing obligation of the registrant under any of the following provisions: </FONT></P> <P
STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2"><FONT FACE="WINGDINGS">&#168;</FONT></FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Written communications pursuant to Rule 425 under the Securities Act (17 CFR 230.425) </FONT></TD></TR></TABLE> <P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>

<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2"><FONT FACE="WINGDINGS">&#168;</FONT></FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Soliciting material pursuant to Rule 14a-12 under the Exchange Act (17 CFR 240.14a-12) </FONT></TD></TR></TABLE> <P
STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2"><FONT FACE="WINGDINGS">&#168;</FONT></FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Pre-commencement communications pursuant to Rule 14d-2(b) under the Exchange Act (17 CFR 240.14d-2(b)) </FONT></TD></TR></TABLE> <P
STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2"><FONT FACE="WINGDINGS">&#168;</FONT></FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Pre-commencement communications pursuant to Rule 13e-4(c) under the Exchange Act (17 CFR 240.13e-4(c)) </FONT></TD></TR></TABLE> <P
STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P> <P STYLE="line-height:0px;margin-top:0px;margin-bottom:0px;border-bottom:0.5pt solid #000000">&nbsp;</P> <P
STYLE="line-height:3px;margin-top:0px;margin-bottom:2px;border-bottom:0.5pt solid #000000">&nbsp;</P>

<p Style='page-break-before:always'>
<HR  SIZE="3" COLOR="#999999" WIDTH="100%" ALIGN="CENTER">

<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="9%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2"><B>Item&nbsp;8.01.</B></FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2"><B>Other Events. </B></FONT></TD></TR></TABLE> <P STYLE="margin-top:6px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">On Friday, September&nbsp;19, 2008, SEI Investments
Company posted to its website at www.seic.com the announcement attached as Exhibit 99.1 regarding the temporary action by the U.S. Securities and Exchange Commission to respond to market developments. </FONT></P> <P
STYLE="margin-top:12px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">As provided in General Instruction B.2 to Form 8-K, the information furnished in this Item&nbsp;8.01 and Exhibit 99.1 hereto shall not be deemed &#147;filed&#148; for
purposes of Section&nbsp;18 of the Securities and Exchange Act of 1934, as amended, nor shall it be deemed incorporated by reference in any filing with the Securities and Exchange Commission, except as shall be expressly provided by specific
reference in such filing. </FONT></P> <P STYLE="font-size:18px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="9%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2"><B>Item&nbsp;9.01.</B></FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2"><B>Financial Statements and Exhibits. </B></FONT></TD></TR></TABLE> <P STYLE="font-size:6px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE STYLE="BORDER-COLLAPSE:COLLAPSE" BORDER="0" CELLPADDING="0" CELLSPACING="0" WIDTH="100%">
<TR>
<TD WIDTH="4%"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD WIDTH="4%" VALIGN="top" ALIGN="left"><FONT FACE="Times New Roman" SIZE="2">(d)</FONT></TD>
<TD ALIGN="left" VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Exhibits. </FONT></TD></TR></TABLE> <P STYLE="margin-top:6px;margin-bottom:0px; text-indent:4%"><FONT FACE="Times New Roman" SIZE="2">99.1&nbsp;&nbsp;&nbsp;&nbsp;SEI Investor Notice
dated September&nbsp;19, 2008 of SEI Investments Company. </FONT></P> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">2 </FONT></P>


<p Style='page-break-before:always'>
<HR  SIZE="3" COLOR="#999999" WIDTH="100%" ALIGN="CENTER">
 <P STYLE="margin-top:0px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2"><B>SIGNATURES </B></FONT></P> <P STYLE="margin-top:6px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">Pursuant
to the requirements of the Securities Exchange Act of 1934, the registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. </FONT></P> <P
STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0">

<TR>
<TD WIDTH="48%"></TD>
<TD VALIGN="bottom" WIDTH="1%"></TD>
<TD WIDTH="2%"></TD>
<TD VALIGN="bottom" WIDTH="1%"></TD>
<TD WIDTH="48%"></TD></TR>
<TR>
<TD VALIGN="top"></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" COLSPAN="3"><FONT FACE="Times New Roman" SIZE="2">SEI INVESTMENTS COMPANY</FONT></TD></TR>
<TR>
<TD HEIGHT="16"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD>
<TD HEIGHT="16" COLSPAN="2"></TD></TR>
<TR>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">Date: September&nbsp;19, 2008</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">By:</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"> <P STYLE="margin-top:0px;margin-bottom:1px;border-bottom:1px solid #000000"><FONT FACE="Times New Roman" SIZE="2">/s/ Dennis J. McGonigle</FONT></P></TD></TR>
<TR>
<TD VALIGN="top"></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">Dennis J. McGonigle</FONT></TD></TR>
<TR>
<TD VALIGN="top"></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom"><FONT FACE="Times New Roman" SIZE="2">Chief Financial Officer</FONT></TD></TR>
</TABLE> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">3 </FONT></P>


<p Style='page-break-before:always'>
<HR  SIZE="3" COLOR="#999999" WIDTH="100%" ALIGN="CENTER">
 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2"><B>EXHIBIT INDEX </B></FONT></P> <P STYLE="font-size:12px;margin-top:0px;margin-bottom:0px">&nbsp;</P>
<TABLE CELLSPACING="0" CELLPADDING="0" WIDTH="100%" BORDER="0" ALIGN="center">

<TR>
<TD></TD>
<TD VALIGN="bottom" WIDTH="4%"></TD>
<TD WIDTH="93%"></TD></TR>
<TR>
<TD VALIGN="bottom" NOWRAP> <P STYLE="border-bottom:1px solid #000000;width:28pt"><FONT FACE="Times New Roman" SIZE="1"><B>Exhibit<BR>Number</B></FONT></P></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="bottom" STYLE="border-bottom:1px solid #000000"> <P STYLE="margin-top:0px;margin-bottom:1px"><FONT FACE="Times New Roman" SIZE="1"><B>Description</B></FONT></P></TD></TR>
<TR>
<TD VALIGN="top" NOWRAP><FONT FACE="Times New Roman" SIZE="2">99.1</FONT></TD>
<TD VALIGN="bottom"><FONT SIZE="1">&nbsp;</FONT></TD>
<TD VALIGN="top"><FONT FACE="Times New Roman" SIZE="2">SEI Investor Notice dated September 19, 2008 of SEI Investments Company.</FONT></TD></TR>
</TABLE> <P STYLE="margin-top:0px;margin-bottom:0px"><FONT SIZE="1">&nbsp;</FONT></P>
 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="center"><FONT FACE="Times New Roman" SIZE="2">4 </FONT></P>

</BODY></HTML>
</TEXT>
</DOCUMENT>
<DOCUMENT>
<TYPE>EX-99.1
<SEQUENCE>2
<FILENAME>dex991.htm
<DESCRIPTION>SEI INVESTOR NOTICE
<TEXT>
<HTML><HEAD>
<TITLE>SEI Investor Notice</TITLE>
</HEAD>
 <BODY BGCOLOR="WHITE">
 <P STYLE="margin-top:0px;margin-bottom:0px" ALIGN="right"><FONT FACE="Times New Roman" SIZE="2"><B>Exhibit 99.1 </B></FONT></P> <P STYLE="margin-top:18px;margin-bottom:0px"><FONT FACE="Times New Roman"
SIZE="2"><B>SEI Covered by SEC Short Selling Order </B></FONT></P> <P STYLE="margin-top:6px;margin-bottom:0px"><FONT FACE="Times New Roman" SIZE="2">With respect to Release 34-58592 of the Securities and Exchange Commission, &#147;Emergency Order
Pursuant to Section&nbsp;12(k)(2) of the Securities Exchange Act of 1934 Taking Temporary Action to Respond to Market Developments&#148;, the SIC code of the Company is 6211, as reported in the Company&#146;s Edgar Filings. Consequently, the Common
Stock of the Company is covered by the order of the Commission described in that release restricting short sales. </FONT></P>
</BODY></HTML>
</TEXT>
</DOCUMENT>
</SUBMISSION>
