<SEC-DOCUMENT>0000312348-25-000022.txt : 20250515
<SEC-HEADER>0000312348-25-000022.hdr.sgml : 20250515
<ACCEPTANCE-DATETIME>20250515093653
ACCESSION NUMBER:		0000312348-25-000022
CONFORMED SUBMISSION TYPE:	SCHEDULE 13G/A
PUBLIC DOCUMENT COUNT:		1
FILED AS OF DATE:		20250515
DATE AS OF CHANGE:		20250515

SUBJECT COMPANY:	

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			SEI INVESTMENTS CO
		CENTRAL INDEX KEY:			0000350894
		STANDARD INDUSTRIAL CLASSIFICATION:	SECURITY BROKERS, DEALERS & FLOTATION COMPANIES [6211]
		ORGANIZATION NAME:           	09 Crypto Assets
		EIN:				231707341
		STATE OF INCORPORATION:			PA
		FISCAL YEAR END:			1231

	FILING VALUES:
		FORM TYPE:		SCHEDULE 13G/A
		SEC ACT:		1934 Act
		SEC FILE NUMBER:	005-34968
		FILM NUMBER:		25949368

	BUSINESS ADDRESS:	
		STREET 1:		1 FREEDOM VALLEY DRIVE
		CITY:			OAKS
		STATE:			PA
		ZIP:			19456-1100
		BUSINESS PHONE:		6106761000

	MAIL ADDRESS:	
		STREET 1:		1 FREEDOM VALLEY DRIVE
		CITY:			OAKS
		STATE:			PA
		ZIP:			19456-1100

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	SEI INVESTMENT CO
		DATE OF NAME CHANGE:	20040806

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	SEI CORP
		DATE OF NAME CHANGE:	19920703

FILED BY:		

	COMPANY DATA:	
		COMPANY CONFORMED NAME:			LOOMIS SAYLES & CO L P
		CENTRAL INDEX KEY:			0000312348
		ORGANIZATION NAME:           	
		EIN:				043200030

	FILING VALUES:
		FORM TYPE:		SCHEDULE 13G/A

	BUSINESS ADDRESS:	
		STREET 1:		ONE FINANCIAL CTR
		STREET 2:		LEGAL & COMPLIANCE, 5TH FLOOR
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02111
		BUSINESS PHONE:		617-748-1761

	MAIL ADDRESS:	
		STREET 1:		ONE FINANCIAL CENTER
		STREET 2:		5TH FLOOR
		CITY:			BOSTON
		STATE:			MA
		ZIP:			02111

	FORMER COMPANY:	
		FORMER CONFORMED NAME:	LOOMIS SAYLES & CO INC
		DATE OF NAME CHANGE:	19920929
</SEC-HEADER>
<DOCUMENT>
<TYPE>SCHEDULE 13G/A
<SEQUENCE>1
<FILENAME>primary_doc.xml
<TEXT>
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<headerData>
	<submissionType>SCHEDULE 13G/A</submissionType>
	<previousAccessionNumber>0000312348-25-000015</previousAccessionNumber>
	<filerInfo>
		<filer>
			<filerCredentials>
				<cik>0000312348</cik>
				<ccc>XXXXXXXX</ccc>
			</filerCredentials>
		</filer>
		<liveTestFlag>LIVE</liveTestFlag>


	</filerInfo>
</headerData>
<formData>
	<coverPageHeader>
		<amendmentNo>14</amendmentNo>
		<securitiesClassTitle>Common Stock</securitiesClassTitle>
		<eventDateRequiresFilingThisStatement>03/31/2025</eventDateRequiresFilingThisStatement>
		<issuerInfo>
			<issuerCik>0000350894</issuerCik>
			<issuerName>SEI Investments Co</issuerName>
			<issuerCusip>784117103</issuerCusip>
			<issuerPrincipalExecutiveOfficeAddress>
				<com:street1>1 FREEDOM VALLEY DRIVE</com:street1>
				<com:city>OAKS</com:city>
				<com:stateOrCountry>PA</com:stateOrCountry>
				<com:zipCode>19456-1100</com:zipCode>
			</issuerPrincipalExecutiveOfficeAddress>
		</issuerInfo>
		<designateRulesPursuantThisScheduleFiled>
			<designateRulePursuantThisScheduleFiled>Rule 13d-1(d)</designateRulePursuantThisScheduleFiled>
		</designateRulesPursuantThisScheduleFiled>
	</coverPageHeader>
	<coverPageHeaderReportingPersonDetails>

		<reportingPersonName>Loomis, Sayles &amp; Co., L.P.</reportingPersonName>
		<citizenshipOrOrganization>DE</citizenshipOrOrganization>
		<reportingPersonBeneficiallyOwnedNumberOfShares>
			<soleVotingPower>7096177.0</soleVotingPower>
			<sharedVotingPower>0</sharedVotingPower>
			<soleDispositivePower>0</soleDispositivePower>
			<sharedDispositivePower>0</sharedDispositivePower>
		</reportingPersonBeneficiallyOwnedNumberOfShares>
		<reportingPersonBeneficiallyOwnedAggregateNumberOfShares>8720520.67</reportingPersonBeneficiallyOwnedAggregateNumberOfShares>
		<classPercent>6.87</classPercent>
		<typeOfReportingPerson>IA</typeOfReportingPerson>
	</coverPageHeaderReportingPersonDetails>
	<items>
		<item1>
			<issuerName>SEI Investments Co</issuerName>
			<issuerPrincipalExecutiveOfficeAddress>1 FREEDOM VALLEY DRIVE, OAKS, PA, 19456-1100</issuerPrincipalExecutiveOfficeAddress>
		</item1>
		<item2>
			<filingPersonName>Loomis, Sayles &amp; Co., L.P.</filingPersonName>
			<principalBusinessOfficeOrResidenceAddress>One Financial Center Boston, MA  02111</principalBusinessOfficeOrResidenceAddress>
			<citizenship>United States</citizenship>
		</item2>
		<item3>
			<notApplicableFlag>N</notApplicableFlag>
			<typeOfPersonFiling>IA</typeOfPersonFiling>
		</item3>
		<item4>
			<amountBeneficiallyOwned>8720520.67</amountBeneficiallyOwned>
			<classPercent>6.87</classPercent>
			<numberOfSharesPersonHas>
				<solePowerOrDirectToVote>7096177.0</solePowerOrDirectToVote>
				<sharedPowerOrDirectToVote>0</sharedPowerOrDirectToVote>
				<solePowerOrDirectToDispose>0</solePowerOrDirectToDispose>
				<sharedPowerOrDirectToDispose>0</sharedPowerOrDirectToDispose>
			</numberOfSharesPersonHas>
		</item4>
		<item5>
			<notApplicableFlag>Y</notApplicableFlag>
			<classOwnership5PercentOrLess>N</classOwnership5PercentOrLess>
		</item5>
		<item6>
			<notApplicableFlag>N</notApplicableFlag>
			<ownershipMoreThan5PercentOnBehalfOfAnotherPerson>Clients of Reporting Person have such a right, none of whom has such interest relating to more than 5% of any class.</ownershipMoreThan5PercentOnBehalfOfAnotherPerson>
		</item6>
		<item7>
			<notApplicableFlag>Y</notApplicableFlag>
		</item7>
		<item8>
			<notApplicableFlag>Y</notApplicableFlag>
		</item8>
		<item9>
			<notApplicableFlag>Y</notApplicableFlag>
		</item9>
		<item10>
			<notApplicableFlag>N</notApplicableFlag>
			<certifications>By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired andare held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect ofchanging or influencing the control of the issuer of the securities and were not acquired and are not held in connection withor as a participant in any transaction having that purpose or effect, other than activities solely in connection with anomination under 240.14a-11. </certifications>
		</item10>
	</items>
	<signatureInformation>
			<reportingPersonName>Loomis, Sayles &amp; Co., L.P.</reportingPersonName>
		<signatureDetails>
			<signature>Mari Shimokawa</signature>
			<title>Deputy Chief Compliance Officer</title>
			<date>05/13/2025</date>
		</signatureDetails>
	</signatureInformation>
</formData>
</edgarSubmission>
</XML>
</TEXT>
</DOCUMENT>
</SEC-DOCUMENT>
