SEIC / SEI Investments Company - SEC Filings, Annual Report, Proxy Statement

SEI Investments Company
US ˙ NasdaqGS ˙ US7841171033

Basic Stats
LEI 5LJTIFADGZ6XH1RVOC11
CIK 350894
SEC Filings
All companies that sell securities in the United States must register with the Securities and Exchange Commission (SEC) and file reports on a regular basis. These reports include company annual reports (10K, 10Q), news updates (8K), investor presentations (found in 8Ks), insider trades (form 4), ownership reports (13D, and 13G), and reports related to the specific securities sold, such as registration statements and prospectus. This page shows recent SEC filings related to SEI Investments Company
SEC Filings (Chronological Order)
This page provides a complete, chronological list of SEC Filings, excluding ownership filings which we provide elsewhere.
August 19, 2025 EX-10.1

Execution Version DB1/ 161233805.4 Published CUSIP Number: 78411SAL1 Revolving Credit CUSIP Number: 78411SAM9 $500,000,000 CREDIT AGREEMENT dated as of August 18, 2025, by and among SEI INVESTMENTS COMPANY, as Borrower, the Lenders referred to herein

ex101usbank-seiinvestmen Execution Version DB1/ 161233805.4 Published CUSIP Number: 78411SAL1 Revolving Credit CUSIP Number: 78411SAM9 $500,000,000 CREDIT AGREEMENT dated as of August 18, 2025, by and among SEI INVESTMENTS COMPANY, as Borrower, the Lenders referred to herein, as Lenders, and U.S. BANK NATIONAL ASSOCIATION, as Administrative Agent, Swingline Lender and Issuing Lender U.S. BANK NATI

August 19, 2025 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 August 18, 2025 Date of report (Date of earliest event reported) SEI INVESTMENTS CO

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 August 18, 2025 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission Fi

July 28, 2025 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2025 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OF 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period fromto Commission File Number: 0-10200 SEI INVESTMENTS COMPANY

July 23, 2025 EX-99.2

SEI Investments Company (NASDAQ: SEIC) Q2 2025 Earnings Presentation This presentation contains forward-looking statements within the meaning or the rules and regulations of the Securities and Exchange Commission. In some cases you can identify forwa

q22025seicearningspresen SEI Investments Company (NASDAQ: SEIC) Q2 2025 Earnings Presentation This presentation contains forward-looking statements within the meaning or the rules and regulations of the Securities and Exchange Commission.

July 23, 2025 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 July 23, 2025 Date of report (Date of earliest event reported) SEI INVESTMENTS COMP

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 July 23, 2025 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission File

July 23, 2025 EX-99.1

SEI Reports Second-Quarter 2025 Financial Results

Investor contact: Media contact: Brad Burke Leslie Wojcik SEI SEI +1 610-676-5350 +1 610-676-4191 bburke2@seic.

July 22, 2025 8-K

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 July 16, 2025 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in its charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission

July 22, 2025 EX-99.1

© 2025 SEI® 1 Media Contact: Investor Contact: Leslie Wojcik Brad Burke SEI SEI +1 610-676-4191 +1 610-676-5350 [email protected] [email protected] Pages: 2 FOR IMMEDIATE RELEASE SEI Appoints Karin Risi and Tom Naratil to Board of Directors Evolution o

corprisinaratilxbodrls7 © 2025 SEI® 1 Media Contact: Investor Contact: Leslie Wojcik Brad Burke SEI SEI +1 610-676-4191 +1 610-676-5350 lwojcik@seic.

July 18, 2025 EX-99.2

July 18, 2025 Enhancing SEI’s wealth management ecosystem. SEI partnership with Stratos Wealth Holdings 1 2 Safe Harbor Statement This presentation contains forward-looking statements within the meaning or the rules and regulations of the Securities

exh992corpeclipsestrateg July 18, 2025 Enhancing SEI’s wealth management ecosystem.

July 18, 2025 EX-99.1

© 2025 SEI® 1 Company Contact: Media Contact: Leslie Wojcik Eric Hazard SEI Vested +1 610-676-4191 1+ 917-765-8720 [email protected] [email protected] Pages: 3 FOR IMMEDIATE RELEASE SEI and Stratos Wealth Holdings Announce Strategic Investment and

© 2025 SEI® 1 Company Contact: Media Contact: Leslie Wojcik Eric Hazard SEI Vested +1 610-676-4191 1+ 917-765-8720 lwojcik@seic.

July 18, 2025 8-K

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 July 17, 2025 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission File

July 1, 2025 8-K

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 June 30, 2025 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in its charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission

July 1, 2025 EX-99.1

© 2025 SEI® 1 Company Contact: Media Contact: Annabel Greenberg Anthony Silverman Aquiline Apella Advisors +44 7717-252-307 +44 7818-036-579 [email protected] [email protected] Leslie Wojcik Kerry Mullen SEI Vested +1 610-676-4191 +1

© 2025 SEI® 1 Company Contact: Media Contact: Annabel Greenberg Anthony Silverman Aquiline Apella Advisors +44 7717-252-307 +44 7818-036-579 agreenberg@aquiline.

June 24, 2025 11-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K (Mark One) x ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2024 ¨ TRANSITION REPORT PURSUANT TO

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K (Mark One) x ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2024 OR ¨ TRANSITION REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file Number 0-10200 A. Full title of the plan and

June 5, 2025 8-K

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 June 5, 2025 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission File

June 5, 2025 EX-99.1

©2025 SEI SEI Investments William Blair Growth Stock Conference June 5, 2025 ©2025 SEI Safe Harbor Statement This presentation contains forward-looking statements within the meaning or the rules and regulations of the Securities and Exchange Commissi

seicwilliamblairpresenta ©2025 SEI SEI Investments William Blair Growth Stock Conference June 5, 2025 ©2025 SEI Safe Harbor Statement This presentation contains forward-looking statements within the meaning or the rules and regulations of the Securities and Exchange Commission.

May 28, 2025 8-K

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 May 28, 2025 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in its charter) Pennsylvania 0-10200 23-1707341 (State or other jurisdiction of incorporation) (Commission F

May 28, 2025 EX-99.1

© 2025 SEI® 1 Investor Contact: Media Contact: Brad Burke Leslie Wojcik SEI SEI +1 610-676-5350 +1 610-676-4191 [email protected] [email protected] Pages: 1 FOR IMMEDIATE RELEASE SEI Declares Dividend of $0.49 per Share OAKS, Pa., May 28, 2025 – The Bo

© 2025 SEI® 1 Investor Contact: Media Contact: Brad Burke Leslie Wojcik SEI SEI +1 610-676-5350 +1 610-676-4191 bburke2@seic.

May 7, 2025 DEFA14A

UNITED STATES

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒Filed by a party other than the Registrant ☐ Check the appropriate box: ☐Preliminary Proxy Statement ☐Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)

April 28, 2025 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2025 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OF 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period fromto Commission File Number: 0-10200 SEI INVESTMENTS COMPANY

April 23, 2025 EX-99.1

SEI Reports First-Quarter 2025 Financial Results

Investor contact: Media contact: Brad Burke Leslie Wojcik SEI SEI +1 610-676-5350 +1 610-676-4191 bburke2@seic.

April 23, 2025 8-K

Regulation FD Disclosure, Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 April 23, 2025 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission Fil

April 23, 2025 EX-99.2

SEI Investments Company (NASDAQ: SEIC) Q1 2025 Earnings Presentation This presentation contains forward-looking statements within the meaning or the rules and regulations of the Securities and Exchange Commission. In some cases you can identify forwa

SEI Investments Company (NASDAQ: SEIC) Q1 2025 Earnings Presentation This presentation contains forward-looking statements within the meaning or the rules and regulations of the Securities and Exchange Commission.

April 14, 2025 DEF 14A

DEF 14A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒Filed by a party other than the Registrant ☐ Check the appropriate box: ☐Preliminary Proxy Statement ☐Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)

March 18, 2025 EX-99.1

© 2025 SEI® 1 Investor Relations Contact: Media Contact: Brad Burke Leslie Wojcik SEI SEI +1 610-676-5350 +1 610-676-4191 [email protected] [email protected] Pages: 1 FOR IMMEDIATE RELEASE SEI Increases Stock Share Repurchase Program by $500 Million OA

© 2025 SEI® 1 Investor Relations Contact: Media Contact: Brad Burke Leslie Wojcik SEI SEI +1 610-676-5350 +1 610-676-4191 bburke2@seic.

March 18, 2025 8-K

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 March 18, 2025 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in its charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission

February 27, 2025 EX-99.1

© 2025 SEI® 1 Company Contact: Media Contact: Annabel Greenberg Anthony Silverman Aquiline Apella Advisors +44 7717-252-307 +44 7818-036-579 [email protected] [email protected] Leslie Wojcik Kerry Mullen SEI Vested +1 610-676-4191 +1

© 2025 SEI® 1 Company Contact: Media Contact: Annabel Greenberg Anthony Silverman Aquiline Apella Advisors +44 7717-252-307 +44 7818-036-579 agreenberg@aquiline.

February 27, 2025 8-K

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 February 27, 2025 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in its charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commiss

February 25, 2025 8-K

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 February 25, 2025 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in its charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commiss

February 25, 2025 EX-99.1

© 2025 SEI® 1 Company Contact: Media Contact: Leslie Wojcik Kerry Mullen SEI Vested +1 610-676-4191 +1 917-765-8720 [email protected] [email protected] Pages: 2 FOR IMMEDIATE RELEASE SEI Executive Vice President Sean Denham to Lead Global Operatio

© 2025 SEI® 1 Company Contact: Media Contact: Leslie Wojcik Kerry Mullen SEI Vested +1 610-676-4191 +1 917-765-8720 lwojcik@seic.

February 20, 2025 EX-99.4

Financial Statements of LSV Asset Management dated December 31, 2024 and 2023.

EXHIBIT 99.4 LSV Asset Management Financial Statements As of December 31, 2024 and 2023 and for the years in the three-year period ended December 31, 2024 LSV Asset Management Table of Contents December 31, 2024 Page Independent Auditors' Report 1 Financial Statements Balance Sheets 3 Statements of Operations 4 Statements of Changes in Partners' Capital 5 Statements of Cash Flows 6 Notes to Financ

February 20, 2025 EX-19

SEI Investments Company - Insider Trading Policy

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February 20, 2025 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2024 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period fromto Commission File Number: 0-10200 SEI INVESTMENTS COMPANY (Exa

February 20, 2025 EX-10.13

2024 Omnibus Equity Compensation Plan Notice of Nonqualified Stock Option Award.

#864915v6 SEI INVESTMENTS COMPANY 2024 OMNIBUS EQUITY COMPENSATION PLAN NOTICE OF NONQUALIFIED STOCK OPTION AWARD Pursuant to the terms and conditions of the individual Nonqualified Stock Option Award Agreement (the “Award Agreement”), attached hereto as Attachment A, and the SEI Investments Company 2024 Omnibus Equity Compensation Plan, as amended from time to time (the “Plan”), attached hereto a

February 20, 2025 EX-21

Subsidiaries of the Registrant.

EXHIBIT 21 SUBSIDIARIES OF THE REGISTRANT NAME JURISDICTION OF ORGANIZATION OR INCORPORATION SEI Investments Distribution Co.

January 29, 2025 EX-99.2

SEI Investments Company (NASDAQ: SEIC) Q4 2024 Earnings Presentation This presentation contains forward-looking statements within the meaning or the rules and regulations of the Securities and Exchange Commission. In some cases you can identify forwa

SEI Investments Company (NASDAQ: SEIC) Q4 2024 Earnings Presentation This presentation contains forward-looking statements within the meaning or the rules and regulations of the Securities and Exchange Commission.

January 29, 2025 8-K

Regulation FD Disclosure, Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 January 29, 2025 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission F

January 29, 2025 EX-99.1

SEI Reports Fourth-Quarter 2024 Financial Results

EX-99.1 2 seic-earningsreleaseex9910.htm PRESS RELEASE Investor contact: Media contact: Brad Burke Leslie Wojcik SEI SEI +1 610-676-5350 +1 610-676-4191 [email protected] [email protected] Pages: 10 FOR IMMEDIATE RELEASE SEI Reports Fourth-Quarter 2024 Financial Results OAKS, Pa., Jan. 29, 2025 – SEI Investments Company (NASDAQ:SEIC) today announced financial results for the fourth quarter 2024. Rel

January 17, 2025 8-K/A

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K/A (Amendment No. 1) CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 January 14, 2025 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorpor

January 17, 2025 EX-99.1

January 2025 SEI Investor Overview. Notice: The End Notes and disclosure regarding forward-looking statements appearing at the end of this presentation are an integral part of this presentation and should be read in conjunction with the relevant mate

January 2025 SEI Investor Overview. Notice: The End Notes and disclosure regarding forward-looking statements appearing at the end of this presentation are an integral part of this presentation and should be read in conjunction with the relevant materials. See slides 15, 17 and 18 at the back of this presentation for information related to the financial metrics and defined terms in this presentati

January 14, 2025 8-K

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 January 14, 2025 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission F

January 14, 2025 EX-99.1

January 2025 SEI Investor Overview. Notice: The End Notes and disclosure regarding forward-looking statements appearing at the end of this presentation are an integral part of this presentation and should be read in conjunction with the relevant mate

January 2025 SEI Investor Overview. Notice: The End Notes and disclosure regarding forward-looking statements appearing at the end of this presentation are an integral part of this presentation and should be read in conjunction with the relevant materials. See slides 15, 17 and 18 at the back of this presentation for information related to the financial metrics and defined terms in this presentati

December 12, 2024 8-K

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 December 12, 2024 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in its charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commiss

December 12, 2024 EX-99.1

© 2024 SEI® 1 Investor Contact: Media Contact: Brad Burke Leslie Wojcik SEI SEI +1 610-676-5350 +1 610-676-4191 [email protected] [email protected] Pages: 1 FOR IMMEDIATE RELEASE SEI Declares Dividend of $0.49 per Share OAKS, Pa., Dec. 12, 2024 – The B

© 2024 SEI® 1 Investor Contact: Media Contact: Brad Burke Leslie Wojcik SEI SEI +1 610-676-5350 +1 610-676-4191 bburke2@seic.

December 11, 2024 8-K

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 December 10, 2024 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission

December 11, 2024 EX-99.1

1 © 2024 SEI Company Contact: Media Contact: Emily Baldwin Kerry Mullen SEI Vested +1 610-676-3262 +1 917-765-8720 [email protected] [email protected] Pages: 3 FOR IMMEDIATE RELEASE SEI Acquires LifeYield New, Fully Bundled Technology Solution to

1 © 2024 SEI Company Contact: Media Contact: Emily Baldwin Kerry Mullen SEI Vested +1 610-676-3262 +1 917-765-8720 ebaldwin@seic.

October 25, 2024 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2024 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OF 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period fromto Commission File Number: 0-10200 SEI INVESTMENTS COM

October 25, 2024 EX-10.1

Employment Agreement, dated June 6, 2024, between Michael Lane and the Registrant.

Exhibit 10.1 May 23, 2024 Michael Lane [RESIDENCE ADDRESS OMITTED] Dear Michael: On behalf of SEI, we are pleased to extend this offer of employment to you, to perform the role of Executive Vice President - Asset Management at SEI. The starting salary will be approximately $26,923.07 bi-weekly, which is $700,000.00 when annualized. Should you accept this offer, you will begin work as a full-time e

October 23, 2024 EX-99.2

© 2024 SEI 1 Investor Relations Contact: Media Contact: Brad Burke Leslie Wojcik SEI SEI +1 610-676-5350 +1 610-676-4191 [email protected] [email protected] Pages: 1 FOR IMMEDIATE RELEASE SEI Increases Stock Share Repurchase Program by $400 Million OAK

© 2024 SEI 1 Investor Relations Contact: Media Contact: Brad Burke Leslie Wojcik SEI SEI +1 610-676-5350 +1 610-676-4191 bburke2@seic.

October 23, 2024 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 October 22, 2024 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission F

October 23, 2024 EX-99.1

SEI Reports Third-Quarter 2024 Financial Results Net Sales Events, AUM, and AUA Drive Record Quarter

Investor contact: Media contact: Brad Burke Leslie Wojcik SEI SEI +1 610-676-5350 +1 610-676-4191 bburke2@seic.

August 30, 2024 EX-99.16

2023 Corporate sustainability report. SEI INVESTMENTS COMPANY 1Sustainability reportB Sustainability report Our unique position at the center of the financial services industry enables us to build deep connections across our clients, markets, and com

2023 Corporate sustainability report. SEI INVESTMENTS COMPANY 1Sustainability reportB Sustainability report Our unique position at the center of the financial services industry enables us to build deep connections across our clients, markets, and communities, and we believe these connections can help build a sustainable future. Our values are the foundation from which we drive our company’s and ou

August 30, 2024 8-K

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 August 30, 2024 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission Fi

July 26, 2024 EX-10.3

Amendment No. 1 to Employee Stock Purchase Plan as Amended and Restated on April 21, 2020. (Incorporated by reference to exhibit 10.3 to the Registrant's Quarterly Report on Form 10-Q for the quarterly period ended June 30, 2024.)

#841944v8 AMENDMENT NO. 1 TO THE SEI INVESTMENTS COMPANY EMPLOYEE STOCK PURCHASE PLAN THIS AMENDMENT, dated as of July 23, 2024, is made by SEI Investments Company (the “Company”) to the SEI Investments Company Employee Stock Purchase Plan (the “Plan”), as amended and restated as of April 21, 2020. and WHEREAS, the Company maintains the Plan for the benefit of its and its subsidiaries’ eligible em

July 26, 2024 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2024 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OF 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period fromto Commission File Number: 0-10200 SEI INVESTMENTS COMPANY

July 26, 2024 EX-10.1

2024 Omnibus Equity Compensation Plan Form of Restricted Stock Unit Award Notice and Agreement. (Incorporated by reference to exhibit 10.1 to the Registrant's Quarterly Report on Form 10-Q for the quarterly period ended June 30, 2024.)

#864914v6 DB1/ 145023891.6 SEI INVESTMENTS COMPANY 2024 OMNIBUS EQUITY COMPENSATION PLAN NOTICE OF RESTRICTED STOCK UNIT AWARD Pursuant to the terms and conditions of the individual Restricted Stock Unit Award Agreement (the “Award Agreement”), attached hereto as Attachment A, and the SEI Investments Company 2024 Omnibus Equity Compensation Plan, as amended from time to time (the “Plan”), attached

July 26, 2024 EX-10.2

Form of 2024 Omnibus Equity Compensation Plan Nonqualified Stock Option Award Notice and Agreement.

#864915v5 DB1/ 145023872.6 SEI INVESTMENTS COMPANY 2024 OMNIBUS EQUITY COMPENSATION PLAN NOTICE OF NONQUALIFIED STOCK OPTION AWARD Pursuant to the terms and conditions of the individual Nonqualified Stock Option Award Agreement (the “Award Agreement”), attached hereto as Attachment A, and the SEI Investments Company 2024 Omnibus Equity Compensation Plan, as amended from time to time (the “Plan”),

July 26, 2024 EX-FILING FEES

Calculation of Filing Fee Table Form S-8 (Form Type) SEI Investments Company (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered Securities

Exhibit 107 Calculation of Filing Fee Table Form S-8 (Form Type) SEI Investments Company (Exact Name of Registrant as Specified in its Charter) Table 1: Newly Registered Securities Security Type Security Class Title Fee Calculation or Carry Forward Rule Amount Registered (1) Proposed Maximum Offering Price Per Unit (2) Proposed Maximum Aggregate Offering Price (2) Fee Rate Amount of Registration Fee Carry Forward Form Type Carry Forward File Number Carry Forward Initial Effective Date Filing Fee Previously Paid in Connection with Unsold Securities to be Carried Forward Fees to be Paid Equity Common stock, par value $0.

July 26, 2024 S-8

As filed with the Securities and Exchange Commission on July 26, 2024

As filed with the Securities and Exchange Commission on July 26, 2024 Registration No.

July 24, 2024 EX-99.1

SEI Reports Second-Quarter 2024 Financial Results

Investor/media contact: Leslie Wojcik SEI +1 610-676-4191 [email protected] Pages: 9 FOR IMMEDIATE RELEASE SEI Reports Second-Quarter 2024 Financial Results OAKS, Pa., July 24, 2024 – SEI Investments Company (NASDAQ:SEIC) today announced financial results for the second-quarter 2024. Diluted earnings per share were $1.05 in second-quarter 2024 compared to $0.89 in second-quarter 2023. Consolidated

July 24, 2024 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 July 24, 2024 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission File

June 18, 2024 11-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K (Mark One) x ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2023 ¨ TRANSITION REPORT PURSUANT TO

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K (Mark One) x ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2023 OR ¨ TRANSITION REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file Number 0-10200 A. Full title of the plan and

June 18, 2024 EX-99.1

23.1 - Consent of Independent Registered Public Accounting Firm

Exhibit 23.1 Consent of Independent Registered Public Accounting Firm We consent to the incorporation by reference in the registration statement (No. 333-41343) on Form S-8 of our report dated June 18, 2024, with respect to the financial statements and the supplemental Schedule H, Line 4i - Schedule of Assets (Held at End of Year) as of December 31, 2023 of SEI Capital Accumulation Plan. /s/ KPMG

May 30, 2024 EX-10.16

Executive Severance and Change in Control Plan. (Incorporated by reference to exhibit 10.16 to the Registrant's Current Report on Form 8-K dated May 30, 2024.)

ex1016executiveseverance #864974v1 SEI INVESTMENTS COMPANY EXECUTIVE SEVERANCE AND CHANGE OF CONTROL PLAN SEI Investments Company, a Pennsylvania corporation (the “Company”), has adopted this SEI Investments Company Executive Severance and Change of Control Plan (the “Plan”) to provide key employees of the Company and its affiliates and subsidiaries with severance protection under covered circumstances.

May 30, 2024 EX-10.15

2024 Omnibus Equity Compensation Plan, as approved by the Company's shareholders on May 29, 2024.

ex1015seic2024omnibusequ #852344v7 DB1/ 144570925.9 SEI INVESTMENTS COMPANY 2024 OMNIBUS EQUITY COMPENSATION PLAN 1. Purpose Effective as of the Effective Date, the SEI Investments Company 2024 Omnibus Equity Compensation Plan (the “Plan”) is hereby established as a successor to the SEI Investments Company 2014 Omnibus Equity Compensation Plan (the “2014 Plan”). No additional grants shall be made

May 30, 2024 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 May 29, 2024 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPA

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 May 29, 2024 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in its charter) Pennsylvania 0-10200 23-1707341 (State or other jurisdiction of incorporation) (Commission F

May 30, 2024 EX-99.1

1 Investor Contact: Media Contact: Alex Whitelam Leslie Wojcik SEI SEI +1 610-676-4924 +1 610-676-4191 [email protected] [email protected] Pages: 1 FOR IMMEDIATE RELEASE SEI Declares Dividend of $0.46 per Share OAKS, Pa., May 29, 2024 – The Board of

ex991seicdividend5292024 1 Investor Contact: Media Contact: Alex Whitelam Leslie Wojcik SEI SEI +1 610-676-4924 +1 610-676-4191 awhitelam@seic.

April 29, 2024 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2024 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OF 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period fromto Commission File Number: 0-10200 SEI INVESTMENTS COMPANY

April 24, 2024 EX-99.1

SEI Reports First-Quarter 2024 Financial Results

Investor Contact: Media Contact: Alex Whitelam Leslie Wojcik SEI SEI +1 610-676-4924 +1 610-676-4191 awhitelam@seic.

April 24, 2024 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 April 24, 2024 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission Fil

April 23, 2024 EX-99.4

Reclassified Average Asset Balances due to Business Segment Restructuring

Exhibit 99.4 Reclassified Average Asset Balances due to Business Segment Restructuring (In millions) Full Year 1st Qtr. 2nd Qtr. 3rd Qtr. 4th Qtr. Full Year 2022 2023 2023 2023 2023 2023 Private Banks: Equity and fixed-income programs $23,326 $23,576 $23,748 $23,920 $23,309 $23,638 Collective trust fund programs 7 7 7 6 5 6 Liquidity funds 3,834 3,253 3,500 3,585 3,808 3,537 Total assets under man

April 23, 2024 EX-99.3

Reclassified Ending Asset Balances due to Business Segment Restructuring

Exhibit 99.3 Reclassified Ending Asset Balances due to Business Segment Restructuring (In millions) Dec. 31, Mar. 31, Jun. 30, Sept. 30, Dec. 31, 2022 2023 2023 2023 2023 Private Banks: Equity and fixed-income programs $22,377 $23,653 $24,091 $23,039 $24,496 Collective trust fund programs 7 6 7 6 4 Liquidity funds 3,201 3,427 3,433 3,636 3,916 Total assets under management $25,585 $27,086 $27,531

April 23, 2024 EX-99.2

Reclassified Results by Business Segment due to Business Segment Restructuring

Exhibit 99.2 Reclassified Results by Business Segment due to Business Segment Restructuring (In thousands) Full Year 1st Qtr. 2nd Qtr. 3rd Qtr. 4th Qtr. Full Year 2022 2023 2023 2023 2023 2023 Private Banks: Revenues (A) $570,010 $120,902 $132,414 $119,664 $123,337 $496,317 Expenses 467,821 112,462 114,165 111,207 110,656 448,490 Operating Profit 102,189 8,440 18,249 8,457 12,681 47,827 Operating

April 23, 2024 EX-99.1

Reclassified Results by Business Segment due to Business Segment Restructuring Year Over Year Comparison

Exhibit 99.1 Reclassified Results by Business Segment due to Business Segment Restructuring Year Over Year Comparison (In thousands) As Reported Amount Restated As Reported Amount Restated 2022 Reclassified 2022 2023 Reclassified 2023 Private Banks: Revenues (A) $575,625 ($5,615) $570,010 $503,317 ($7,000) $496,317 Expenses 473,209 ($5,388) 467,821 455,820 ($7,330) 448,490 Operating Profit 102,416

April 23, 2024 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 April 23, 2024 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in its charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission

April 15, 2024 DEF 14A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A INFORMATION Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)

March 1, 2024 EX-10.1

Consulting Agreement, dated as of February 29, 2024, by and between the Company and Dennis J. McGonigle

1 February 28, 2024 Dennis McGonigle [RESIDENCE ADDRESS OMITTED] Dear Dennis: As we have discussed, your long tenure with and significant contributions to SEI Investments Company and its affiliates (“SEI”) are greatly appreciated.

March 1, 2024 8-K

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 February 29, 2024 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in its charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commiss

February 22, 2024 10-K/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K/A (Amendment No. 1)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K/A (Amendment No. 1) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period fromto Commission File Number: 0-10200 SEI INVE

February 22, 2024 EX-99.14

Financial Statements of LSV Asset Management dated December 31, 2023 and 2022.

EXHIBIT 99.14 LSV Asset Management Financial Statements As of December 31, 2023 and 2022 and for the years in the three-year period ended December 31, 2023 1 LSV Asset Management Table of Contents December 31, 2023 Page Independent Auditors' Report 3 Financial Statements Balance Sheets 5 Statements of Operations 6 Statements of Changes in Partners' Capital 7 Statements of Cash Flows 8 Notes to Fin

February 21, 2024 8-K

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 February 21, 2024 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission

February 21, 2024 EX-99.1

© 2024 SEI 1 Company Contact: Media Contact: Leslie Wojcik Kerry Mullen SEI Vested +1 610-676-4191 +1 917-765-8720 [email protected] [email protected] Pages: 2 FOR IMMEDIATE RELEASE SEI and TIFIN Partner to Power the Future of Wealth Through Artif

© 2024 SEI 1 Company Contact: Media Contact: Leslie Wojcik Kerry Mullen SEI Vested +1 610-676-4191 +1 917-765-8720 lwojcik@seic.

February 20, 2024 EX-99.14

Financial Statements of LSV Asset Management dated December 31, 2023 and 2022.

EXHIBIT 99.14 LSV Asset Management Financial Statements As of December 31, 2023 and 2022 and for the years in the three-year period ended December 31, 2023 1 LSV Asset Management Table of Contents December 31, 2023 Page Independent Auditors' Report 3 Financial Statements Balance Sheets 5 Statements of Operations 6 Statements of Changes in Partners' Capital 7 Statements of Cash Flows 8 Notes to Fin

February 20, 2024 EX-10.5

Employee Stock Purchase Plan as Amended and Restated on April 21, 2020.

DB1/ 109849687.5 SEI INVESTMENTS COMPANY EMPLOYEE STOCK PURCHASE PLAN As Amended and Restated, Effective as of April 21, 2020 ARTICLE I INTRODUCTION Section 1.1 Statement of Purpose. The purpose of the SEI Investments Company Employee Stock Purchase Plan is to provide eligible employees of SEI Investments Company and its participating subsidiaries who wish to become shareholders or to increase the

February 20, 2024 EX-97

Amended and Restated Compensation Recoupment Policy

#845696v3 SEI INVESTMENTS COMPANY AMENDED AND RESTATED COMPENSATION RECOUPMENT POLICY On or around January 2011, the Board of Directors (the “Board”) of SEI Investments Company (the “Company”) adopted a Compensation Recoupment Policy (“Original Policy”) in order to (i) promote actions by officers consistent with their duty to the Company under law and Company’s Code of Conduct, (ii) further the interests of the Company, and (iii) mitigate risk in the Company’s compensation arrangements.

February 20, 2024 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2023 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period fromto Commission File Number: 0-10200 SEI INVESTMENTS COMPANY (Exa

February 20, 2024 EX-21

Subsidiaries of the Registrant.

EXHIBIT 21 SUBSIDIARIES OF THE REGISTRANT NAME JURISDICTION OF ORGANIZATION OR INCORPORATION SEI Investments Distribution Co.

February 13, 2024 SC 13G/A

SEIC / SEI Investments Company / VANGUARD GROUP INC - SCHEDULE 13G/A Passive Investment

SC 13G/A 1 tv01892-seiinvestmentsco.htm SCHEDULE 13G/A SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No.: 10)* Name of issuer: SEI Investments Co Title of Class of Securities: Common Stock CUSIP Number: 784117103 Date of Event Which Requires Filing of this Statement: December 29, 2023 Check the appropriate box to designa

February 5, 2024 8-K

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 January 16, 2024 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in its charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commissi

February 5, 2024 EX-99.3

© 2024 SEI 1 Company Contact: Media Contact: Leslie Wojcik Kerry Mullen SEI Vested +1 610-676-4191 +1 917-765-8720 [email protected] [email protected] Pages: 2 FOR IMMEDIATE RELEASE SEI Appoints Sean Denham as CFO OAKS, Pa., Feb. 5, 2024 – SEI® (N

© 2024 SEI 1 Company Contact: Media Contact: Leslie Wojcik Kerry Mullen SEI Vested +1 610-676-4191 +1 917-765-8720 lwojcik@seic.

February 5, 2024 EX-99.1

Execution Copy EMPLOYMENT AGREEMENT THIS EMPLOYMENT AGREEMENT (this “Agreement”) is entered into by and between SEI Investments Company, a Pennsylvania corporation (the “Company”) and Sean Denham (the “Executive”) as of January 16, 2024. WHEREAS, the

ex991sdenhamemploymentag Execution Copy EMPLOYMENT AGREEMENT THIS EMPLOYMENT AGREEMENT (this “Agreement”) is entered into by and between SEI Investments Company, a Pennsylvania corporation (the “Company”) and Sean Denham (the “Executive”) as of January 16, 2024.

February 5, 2024 EX-99.2

1 AMENDMENT NO. 1 TO EMPLOYMENT AGREEMENT THIS AMENDMENT NO. 1 TO THE EMPLOYMENT AGREEMENT (this “Amendment”), effective as of January 31, 2024 (the “Amendment Effective Date”), is entered into by and between SEI Investments Company (the “Company”) a

1 AMENDMENT NO. 1 TO EMPLOYMENT AGREEMENT THIS AMENDMENT NO. 1 TO THE EMPLOYMENT AGREEMENT (this “Amendment”), effective as of January 31, 2024 (the “Amendment Effective Date”), is entered into by and between SEI Investments Company (the “Company”) and Sean Denham (the “Executive”). RECITALS WHEREAS, SEI and the Executive entered into an Employment Agreement, dated January 16, 2024 (the “Agreement

February 1, 2024 8-K

Notice of Delisting or Failure to Satisfy a Continued Listing Rule or Standard; Transfer of Listing, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 February 1, 2024 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in its charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commissi

January 31, 2024 EX-99.1

SEI Reports Fourth-Quarter 2023 Financial Results

Investor Contact: Media Contact: Alex Whitelam Leslie Wojcik SEI SEI +1 610-676-4924 +1 610-676-4191 awhitelam@seic.

January 31, 2024 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 January 31, 2024 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission F

December 22, 2023 EX-99.1

December 19, 2023 VIA EMAIL Wayne Withrow [Residence Address Omitted] Dear Wayne: This letter will confirm important details regarding your separation of employment from SEI Investments Company (“SEI”), effective February 28, 2024 (the “Separation Da

December 19, 2023 VIA EMAIL Wayne Withrow [Residence Address Omitted] Dear Wayne: This letter will confirm important details regarding your separation of employment from SEI Investments Company (“SEI”), effective February 28, 2024 (the “Separation Date”).

December 22, 2023 8-K

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 December 19, 2023 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in its charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commiss

December 22, 2023 EX-99.2

1 © 2023 SEI Media Contact: Investor Contact: Leslie Wojcik Alex Whitelam SEI SEI +1 610-676-4191 +1 610-676-4924 [email protected] [email protected] Pages: 2 FOR IMMEDIATE RELEASE SEI Announces Wayne Withrow to Step Away OAKS, Pa., Dec. 22, 2023 – S

1 © 2023 SEI Media Contact: Investor Contact: Leslie Wojcik Alex Whitelam SEI SEI +1 610-676-4191 +1 610-676-4924 lwojcik@seic.

December 21, 2023 8-K

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 December 21, 2023 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission

December 21, 2023 EX-99.1

© 2023 SEI 1 Company Contact: Media Contact: Leslie Wojcik Kerry Mullen SEI Vested +1 610-676-4191 +1 917-765-8720 [email protected] [email protected] Pages: 2 FOR IMMEDIATE RELEASE SEI Acquires Altigo SEI to Leverage Unique Industry Position to M

© 2023 SEI 1 Company Contact: Media Contact: Leslie Wojcik Kerry Mullen SEI Vested +1 610-676-4191 +1 917-765-8720 lwojcik@seic.

December 18, 2023 EX-99.1

© 2023 SEI 1 Investor Contact: Media Contact: Alex Whitelam Leslie Wojcik SEI SEI +1 610-676-4924 +1 610-676-4191 [email protected] [email protected] Pages: 1 FOR IMMEDIATE RELEASE SEI Declares Dividend of $0.46 per Share Company Increases Share Repu

© 2023 SEI 1 Investor Contact: Media Contact: Alex Whitelam Leslie Wojcik SEI SEI +1 610-676-4924 +1 610-676-4191 awhitelam@seic.

December 18, 2023 8-K

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 December 15, 2023 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in its charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commiss

October 27, 2023 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2023 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OF 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period fromto Commission File Number: 0-10200 SEI INVESTMENTS COM

October 26, 2023 EX-99.15

2022 Corporate social responsibility report. SEI INVESTMENTS COMPANY Building brave futures.SM ABOUT THE REPORT As a provider of technology and investment solutions that connect the financial services industry, we work with corporations, financial in

2022 Corporate social responsibility report. SEI INVESTMENTS COMPANY Building brave futures.SM ABOUT THE REPORT As a provider of technology and investment solutions that connect the financial services industry, we work with corporations, financial institutions and professionals, and ultra-high-net-worth families to solve problems, manage change, and help protect assets—for growth today and in the

October 26, 2023 8-K

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 October 26, 2023 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission F

October 25, 2023 EX-99.1

1 © 2023 SEI Media Contact: Investor Contact: Leslie Wojcik Alex Whitelam SEI SEI +1 610-676-4191 +1 610-676-4924 [email protected] [email protected] Pages: 2 FOR IMMEDIATE RELEASE SEI Appoints Stephanie Miller to Board of Directors Industry Veteran

1 © 2023 SEI Media Contact: Investor Contact: Leslie Wojcik Alex Whitelam SEI SEI +1 610-676-4191 +1 610-676-4924 lwojcik@seic.

October 25, 2023 8-K

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 October 24, 2023 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in its charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commissi

October 25, 2023 EX-99.1

SEI Reports Third-Quarter 2023 Financial Results

Investor Contact: Media Contact: Alex Whitelam Leslie Wojcik SEI SEI +1 610-676-4924 +1 610-676-4191 awhitelam@seic.

October 25, 2023 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 October 25, 2023 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission F

July 31, 2023 8-K

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 July 26, 2023 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in its charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission

July 28, 2023 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2023 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OF 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period fromto Commission File Number: 0-10200 SEI INVESTMENTS COMPANY

July 26, 2023 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 July 26, 2023 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission File

July 26, 2023 EX-99.1

SEI Reports Second-Quarter 2023 Financial Results

Investor Contact: Media Contact: Alex Whitelam Leslie Wojcik SEI SEI +1 610-676-4924 +1 610-676-4191 awhitelam@seic.

July 14, 2023 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 July 13, 2023 Date of report (Date of earliest event reported) SEI INVESTMENTS COMP

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 July 13, 2023 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in its charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission

July 14, 2023 EX-99.1

© 2023 SEI 1 Company Contact: Media Contact: Leslie Wojcik Amelia Graham SEI Vested +1 610-676-4191 +44 (0)20 7393 477057 [email protected] [email protected] Paul Cuff Feidhlim Macauley XPS Pensions Group Headland +44 (0)20 3978 8625 +44 (0)20 34

ex991igxpsseirls © 2023 SEI 1 Company Contact: Media Contact: Leslie Wojcik Amelia Graham SEI Vested +1 610-676-4191 +44 (0)20 7393 477057 lwojcik@seic.

June 22, 2023 11-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K (Mark One) x ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2022 ¨ TRANSITION REPORT PURSUANT TO

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K (Mark One) x ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2022 OR ¨ TRANSITION REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file Number 0-10200 A. Full title of the plan and

June 22, 2023 EX-99.1

23.1 - Consent of Independent Registered Public Accounting Firm

Exhibit 23.1 Consent of Independent Registered Public Accounting Firm We consent to the incorporation by reference in the registration statement (No. 333-41343) on Form S-8 of our report dated June 22, 2023, with respect to the financial statements (and financial statement schedule) of the SEI Capital Accumulation Plan. /s/ KPMG LLP Philadelphia, Pennsylvania June 22, 2023 11

June 1, 2023 EX-99.1

© 2023 SEI 1 Company/Media Contact: Leslie Wojcik SEI +1 610-676-4191 [email protected] Pages: 1 FOR IMMEDIATE RELEASE SEI Declares Dividend of $0.43 per Share OAKS, Pa., May 31, 2023 – The Board of Directors of SEI Investments Company (NASDAQ: SEIC)

seidividendrls53123 © 2023 SEI 1 Company/Media Contact: Leslie Wojcik SEI +1 610-676-4191 lwojcik@seic.

June 1, 2023 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 May 31, 2023 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPA

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 May 31, 2023 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in its charter) Pennsylvania 0-10200 23-1707341 (State or other jurisdiction of incorporation) (Commission F

April 24, 2023 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2023 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OF 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period fromto Commission File Number: 0-10200 SEI INVESTMENTS COMPANY

April 20, 2023 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 April 20, 2023 Date of report (Date of earliest event reported) SEI INVESTMENTS COM

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 April 20, 2023 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission Fil

April 20, 2023 DEF 14A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. )

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 SCHEDULE 14A Proxy Statement Pursuant to Section 14(a) of the Securities Exchange Act of 1934 (Amendment No. ) Filed by the Registrant ☒ Filed by a party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ Confidential, for Use of the Commission Only (as permitted by Rule 14a-6(e)(2)) ☒ Defin

April 20, 2023 EX-99.1

SEI Reports First-Quarter 2023 Financial Results

Investor Contact: Media Contact: Lindsey Opsahl Leslie Wojcik SEI SEI +1 610-676-4052 +1 610-676-4191 lopsahl@seic.

April 18, 2023 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 April 17, 2023 Date of report (Date of earliest event reported) SEI INVESTMENTS COM

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 April 17, 2023 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in its charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission

April 18, 2023 EX-10.27 1

First Amendment to Credit Agreement dated as of April 17, 2023 among SEI Investments Company, the Lenders, U.S. Bank National Association, as Syndication Agent, Bank of America, N.A., Citizens Bank, N.A., Manufacturers and Traders Trust Company and Regions Bank, as Documentation Agents, and Wells Fargo Bank, National Association, as Administrative Agent (Incorporated by reference to exhibit 10.27.1 to the Registrant's Current Report on Form 8-K dated April 17, 2023.)

wellsfargo-seiinvestment 15870292v2 24740.00076 Execution Version FIRST AMENDMENT TO CREDIT AGREEMENT This FIRST AMENDMENT TO CREDIT AGREEMENT, dated as of April 17, 2023 (this “Amendment”), to that certain Credit Agreement dated as of April 23, 2021, among SEI INVESTMENTS COMPANY, as borrower (the “Borrower”), the Lenders from time to time party thereto, and WELLS FARGO BANK, NATIONAL ASSOCIATION

April 18, 2023 EX-99.1

© 2023 SEI 1 Company/Media Contact: Leslie Wojcik SEI +1 610-676-4191 [email protected] Pages: 1 FOR IMMEDIATE RELEASE SEI Increases Stock Share Repurchase Program by $250 Million OAKS, Pa., April 18, 2023 – The Board of Directors of SEI Investments C

seistockrepurchaserls418 © 2023 SEI 1 Company/Media Contact: Leslie Wojcik SEI +1 610-676-4191 lwojcik@seic.

April 6, 2023 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 March 31, 2023 Date of report (Date of earliest event reported) SEI INVESTMENTS COM

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 March 31, 2023 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in its charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission

February 24, 2023 10-K/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K/A (Amendment No. 1)

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K/A (Amendment No. 1) ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2022 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period fromto Commission File Number: 0-10200 SEI INVE

February 21, 2023 EX-10.2

2014 Omnibus Equity Compensation Plan Stock Option Grant Agreement. (Incorporated by reference to exhibit 10.2 to the Registrant's Annual Report on Form 10-K for the fiscal year ended December 31, 2022.)

exhibit102-2014omnibuseq DB1/ 78413207.3 SEI INVESTMENTS COMPANY 2014 OMNIBUS EQUITY COMPENSATION PLAN NONQUALIFIED STOCK OPTION GRANT This STOCK OPTION GRANT AGREEMENT (this “Agreement”), dated as of (the “Date of Grant”), is delivered by SEI Investments Company (the “Company”) to (the “Grantee”). RECITALS A. The SEI Investments Company 2014 Omnibus Equity Compensation Plan (the “Plan”) provides

February 21, 2023 EX-21

Subsidiaries of the Registrant.

EXHIBIT 21 SUBSIDIARIES OF THE REGISTRANT NAME JURISDICTION OF ORGANIZATION OR INCORPORATION SEI Investments Distribution Co.

February 21, 2023 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2022 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period fromto Commission File Number: 0-10200 SEI INVESTMENTS COMPANY (Exa

February 21, 2023 EX-99.13

Financial Statements of LSV Asset Management dated December 31, 2022 and 2021. (Incorporated by reference to exhibit 99.13 to the Registrant's Annual Report on Form 10-K for the fiscal year ended December 31, 2022.)

EXHIBIT 99.13 LSV Asset Management Financial Statements As of December 31, 2022 and 2021 and for the years in the three-year period ended December 31, 2022 1 LSV Asset Management Table of Contents December 31, 2022 Page Independent Auditors' Report 3 Financial Statements Balance Sheets 5 Statements of Operations 6 Statements of Changes in Partners' Capital 7 Statements of Cash Flows 8 Notes to Fin

February 9, 2023 SC 13G/A

SEIC / SEI Investments Company / VANGUARD GROUP INC - SCHEDULE 13G/A Passive Investment

SC 13G/A 1 tv01863-seiinvestmentsco.htm SCHEDULE 13G/A SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No.: 9)* Name of issuer: SEI Investments Co. Title of Class of Securities: Common Stock CUSIP Number: 784117103 Date of Event Which Requires Filing of this Statement: December 30, 2022 Check the appropriate box to designa

January 25, 2023 EX-99.1

SEI Reports Fourth-Quarter 2022 Financial Results

Investor Contact: Media Contact: Lindsey Opsahl Leslie Wojcik SEI SEI +1 610-676-4052 +1 610-676-4191 lopsahl@seic.

January 25, 2023 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 January 25, 2023 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission F

December 5, 2022 EX-99.1

© 2022 SEI 1 Company/Media Contact: Leslie Wojcik SEI +1 610-676-4191 [email protected] Pages: 1 FOR IMMEDIATE RELEASE SEI Declares Dividend of $0.43 per Share OAKS, Pa., Dec. 5, 2022 – The Board of Directors of SEI Investments Company (NASDAQ: SEIC)

? 2022 SEI 1 Company/Media Contact: Leslie Wojcik SEI +1 610-676-4191 lwojcik@seic.

December 5, 2022 8-K

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 December 5, 2022 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in its charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commissi

October 28, 2022 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ? QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2022 or ? TRANSITION REPORT PURSUANT TO SECTION 13 OF 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period fromto Commission File Number: 0-10200 SEI INVESTMENTS COM

October 27, 2022 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 October 25, 2022 Date of report (Date of earliest event reported) SEI INVESTMENTS C

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 October 25, 2022 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission F

October 26, 2022 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 October 26, 2022 Date of report (Date of earliest event reported) SEI INVESTMENTS C

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 October 26, 2022 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission F

October 26, 2022 EX-99.1

SEI Reports Third-Quarter 2022 Financial Results

Investor Contact: Media Contact: Lindsey Opsahl Leslie Wojcik SEI SEI +1 610-676-4052 +1 610-676-4191 lopsahl@seic.

August 23, 2022 8-K

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 August 23, 2022 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission Fi

August 23, 2022 EX-99.14

2021 Corporate social responsibility report. SEI Investments Company 1B Throughout 2021, we continued to find opportunity in change, building connections that enable our clients, communities, and employees to make confident decisions for the future.

2021 Corporate social responsibility report. SEI Investments Company 1B Throughout 2021, we continued to find opportunity in change, building connections that enable our clients, communities, and employees to make confident decisions for the future. Our clients? goals often go beyond the technology and investment solutions we provide. We understand that investors increasingly consider how their va

July 25, 2022 EX-10.1

2014 Omnibus Equity Compensation Plan Restricted Stock Unit Agreement. (Incorporated by reference to exhibit 10.1 to the Registrant's Quarterly Report on Form 10-Q for the quarterly period ended June 30, 2022.)

Exhibit 10.1 SEI INVESTMENTS COMPANY 2014 OMNIBUS EQUITY COMPENSATION PLAN RESTRICTED STOCK UNIT AGREEMENT This RESTRICTED STOCK UNIT AGREEMENT (the ?Agreement?), dated as of [ ] (the ?Date of Grant?), is delivered by SEI Investments Company (the ?Company?) to [] (the ?Participant?). RECITALS A. The SEI Investments Company 2014 Omnibus Equity Compensation Plan (the ?Plan?) provides for the grant o

July 25, 2022 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ? QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2022 or ? TRANSITION REPORT PURSUANT TO SECTION 13 OF 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period fromto Commission File Number: 0-10200 SEI INVESTMENTS COMPANY

July 20, 2022 8-K

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 July 18, 2022 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission File

July 20, 2022 EX-99.1

SEI Reports Second-Quarter 2022 Financial Results

Investor Contact: Media Contact: Lindsey Opsahl Leslie Wojcik SEI SEI +1 610-676-4052 +1 610-676-4191 lopsahl@seic.

June 28, 2022 EX-99.1

23.1 - Consent of Independent Registered Public Accounting Firm

Exhibit 23.1 Consent of Independent Registered Public Accounting Firm We consent to the incorporation by reference in the registration statement (No. 333-41343) on Form S-8 of our report dated June 28, 2022, with respect to the financial statements (and financial statement schedule) of the SEI Capital Accumulation Plan. /s/ KPMG LLP Philadelphia, Pennsylvania June 28, 2022 12

June 28, 2022 11-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K (Mark One) x ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2021 ¨ TRANSITION REPORT PURSUANT TO

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K (Mark One) x ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2021 OR ? TRANSITION REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file Number 0-10200 A. Full title of the plan and

June 1, 2022 EX-99.1

© 2022 SEI 1 Company/Media Contact: Leslie Wojcik SEI +1 610-676-4191 [email protected] Pages: 1 FOR IMMEDIATE RELEASE SEI Declares Dividend of $0.40 per Share Company Increases Share Repurchase Program by $200 Million OAKS, Pa., June 1, 2022 – The Bo

? 2022 SEI 1 Company/Media Contact: Leslie Wojcik SEI +1 610-676-4191 lwojcik@seic.

June 1, 2022 8-K

Financial Statements and Exhibits, Other Events, Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 June 1, 2022 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in its charter) Pennsylvania 0-10200 23-1707341 (State or other jurisdiction of incorporation) (Commission F

April 29, 2022 10-Q/A

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q/A Amendment No. 1

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q/A Amendment No. 1 ? QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2022 or ? TRANSITION REPORT PURSUANT TO SECTION 13 OF 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period fromto Commission File Number: 0-10200 SEI I

April 27, 2022 DEF 14A

SCHEDULE 14A INFORMATION PROXY STATEMENT PURSUANT TO SECTION 14(A) OF THE SECURITIES EXCHANGE ACT OF 1934 Filed by the Registrant ☒ Filed by a Party other than the Registrant ☐ Check the appropriate box: ☐ Preliminary Proxy Statement ☐ CONFIDENTIAL,

SCHEDULE 14A INFORMATION PROXY STATEMENT PURSUANT TO SECTION 14(A) OF THE SECURITIES EXCHANGE ACT OF 1934 Filed by the Registrant ? Filed by a Party other than the Registrant ? Check the appropriate box: ? Preliminary Proxy Statement ? CONFIDENTIAL, FOR USE OF THE COMMISSION ONLY (AS PERMITTED BY RULE 14A-6(E)(2)) ? Definitive Proxy Statement ? Definitive Additional Materials ? Soliciting Material Pursuant to Rule 14a-12 SEI INVESTMENTS COMPANY (Name of Registrant as Specified in Its Charter) N/A (Name of Person(s) Filing Proxy Statement, if other than the Registrant) Payment of Filing Fee (Check the appropriate box): ? No fee required.

April 25, 2022 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ? QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2022 or ? TRANSITION REPORT PURSUANT TO SECTION 13 OF 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period fromto Commission File Number: 0-10200 SEI INVESTMENTS COMPANY

April 20, 2022 EX-99.1

SEI Reports First-Quarter 2022 Financial Results

Investor Contact: Media Contact: Lindsey Opsahl Leslie Wojcik SEI SEI +1 610-676-4052 +1 610-676-4191 lopsahl@seic.

April 20, 2022 EX-99.2

1 © 2022 SEI Media Contact: Investor Contact: Leslie Wojcik Lindsey Opsahl SEI SEI +1 610-676-4191 +1 610-676-4052 [email protected] [email protected] Pages: 2 FOR IMMEDIATE RELEASE SEI Appoints Jonathan Brassington to Board of Directors Senior Technol

1 ? 2022 SEI Media Contact: Investor Contact: Leslie Wojcik Lindsey Opsahl SEI SEI +1 610-676-4191 +1 610-676-4052 lwojcik@seic.

April 20, 2022 8-K

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 April 19, 2022 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission Fil

April 4, 2022 EX-99.1

Execution Copy EMPLOYMENT AGREEMENT THIS EMPLOYMENT AGREEMENT (this “Agreement”) is entered into by and between SEI Investments Company, a Pennsylvania corporation (the “Company”) and Ryan Hicke (the “Executive”) as of March 31, 2022. WHEREAS, the Co

Execution Copy EMPLOYMENT AGREEMENT THIS EMPLOYMENT AGREEMENT (this ?Agreement?) is entered into by and between SEI Investments Company, a Pennsylvania corporation (the ?Company?) and Ryan Hicke (the ?Executive?) as of March 31, 2022.

April 4, 2022 EX-99.3

AMENDED AND RESTATED BY-LAWS OF SEI INVESTMENTS COMPANY (a Pennsylvania Corporation) ARTICLE I Offices and Fiscal Year Section 1.01. Registered Office. The registered office of the corporation in the Commonwealth of Pennsylvania shall be at 1 Freedom

AMENDED AND RESTATED BY-LAWS OF SEI INVESTMENTS COMPANY (a Pennsylvania Corporation) ARTICLE I Offices and Fiscal Year Section 1.

April 4, 2022 EX-99.2

1 © 2022 SEI Media Contact: Investor Contact: Leslie Wojcik Lindsey Opsahl SEI SEI +1 610-676-4191 +1 610-676-4052 [email protected] [email protected] Pages: 2 FOR IMMEDIATE RELEASE SEI Announces Appointment of Ryan Hicke as Next CEO Chairman and Found

1 ? 2022 SEI Media Contact: Investor Contact: Leslie Wojcik Lindsey Opsahl SEI SEI +1 610-676-4191 +1 610-676-4052 lwojcik@seic.

April 4, 2022 8-K

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Amendments to Articles of Incorporation or Bylaws; Change in Fiscal Year, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 March 31, 2022 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in its charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission

March 24, 2022 8-K

Regulation FD Disclosure

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 March 21, 2022 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in its charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission

February 22, 2022 EX-21

Subsidiaries of the Registrant.

EXHIBIT 21 SUBSIDIARIES OF THE REGISTRANT NAME JURISDICTION OF ORGANIZATION OR INCORPORATION SEI Investments Distribution Co.

February 22, 2022 EX-99.12

Financial Statements of LSV Asset Management dated December 31, 2021 and 2020. (Incorporated by reference to exhibit 99.12 to the Registrant's Annual Report on Form 10-K for the fiscal year ended December 31, 2021.)

EXHIBIT 99.12 LSV Asset Management Financial Statements As of December 31, 2021 and 2020 and for the years in the three-year period ended December 31, 2021 LSV Asset Management Table of Contents December 31, 2021 Page Independent Auditors' Report 3 Financial Statements Balance Sheets 5 Statements of Operations 6 Statements of Changes in Partners' Capital 7 Statements of Cash Flows 8 Notes to Finan

February 22, 2022 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ? ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2021 OR ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period fromto Commission File Number: 0-10200 SEI INVESTMENTS COMPANY (Exa

February 10, 2022 SC 13G/A

SEIC / SEI Investments Company / VANGUARD GROUP INC - SCHEDULE 13G/A Passive Investment

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No.: 8)* Name of issuer: SEI Investments Co. Title of Class of Securities: Common Stock CUSIP Number: 784117103 Date of Event Which Requires Filing of this Statement: December 31, 2021 Check the appropriate box to designate the rule pursuant to which this Schedule is filed: ?

January 26, 2022 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 January 26, 2022 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission F

January 26, 2022 EX-99.1

SEI Reports Fourth-Quarter 2021 Financial Results

Investor Contact: Media Contact: Lindsey Opsahl Leslie Wojcik SEI SEI +1 610-676-4052 +1 610-676-4191 lopsahl@seic.

December 28, 2021 8-K

Departure of Directors or Certain Officers; Election of Directors; Appointment of Certain Officers; Compensatory Arrangements of Certain Officers, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 December 26, 2021 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in its charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commiss

December 28, 2021 EX-99.1

© 2021 SEI 1 Company/Media Contact: Leslie Wojcik SEI +1 610-676-4191 [email protected] Pages: 2 FOR IMMEDIATE RELEASE SEI Announces Leadership Change OAKS, Pa., Dec. 28, 2021 – SEI® (NASDAQ: SEIC) today announced the departure of Steve Meyer as an Ex

? 2021 SEI 1 Company/Media Contact: Leslie Wojcik SEI +1 610-676-4191 lwojcik@seic.

December 13, 2021 EX-99.1

© 2021 SEI 1 Company/Media Contact: Leslie Wojcik SEI +1 610-676-4191 [email protected] Pages: 1 FOR IMMEDIATE RELEASE SEI Declares Dividend of $0.40 per Share Company Increases Share Repurchase Program by $200 Million OAKS, Pa., Dec. 13, 2021 – The B

? 2021 SEI 1 Company/Media Contact: Leslie Wojcik SEI +1 610-676-4191 lwojcik@seic.

December 13, 2021 8-K

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 December 10, 2021 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in its charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commiss

November 22, 2021 8-K

Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 November 22, 2021 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in its charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commiss

November 12, 2021 8-K

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 November 12, 2021 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission

November 12, 2021 EX-99.1

Press Release Company Contact: Media Contact: Netanel Spero Kristina Pereira Tully SEI Vested +1 610-676-4556 +1 650-464-0080 [email protected] [email protected] Pages: 2 FOR IMMEDIATE RELEASE SEI Acquires Novus Partners to Broaden Capabilities

Press Release Company Contact: Media Contact: Netanel Spero Kristina Pereira Tully SEI Vested +1 610-676-4556 +1 650-464-0080 nspero@seic.

November 1, 2021 EX-99.13

SEI Investments Company Corporate Social Responsibility Report 202 Alfred P. West, Jr. Chairman and Chief Executive Officer Last year was marked by a pandemic with far- reaching social and economic repercussions, renewed calls to address inequity, an

SEI Investments Company Corporate Social Responsibility Report 202 Alfred P. West, Jr. Chairman and Chief Executive Officer Last year was marked by a pandemic with far- reaching social and economic repercussions, renewed calls to address inequity, and gratefully, the resilience of our front-line workers, communities and families. It was a year that reminded us of the importance of our responsibili

November 1, 2021 8-K

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 November 1, 2021 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission F

October 25, 2021 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ? QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2021 or ? TRANSITION REPORT PURSUANT TO SECTION 13 OF 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period fromto Commission File Number: 0-10200 SEI INVESTMENTS COM

October 20, 2021 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 October 20, 2021 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission F

October 20, 2021 EX-99.1

SEI Reports Third-Quarter 2021 Financial Results

Exhibit 99.1 Investor Contact: Media Contact: Lindsey Opsahl Leslie Wojcik SEI SEI +1 610-676-4052 +1 610-676-4191 [email protected] [email protected] Pages: 8 FOR IMMEDIATE RELEASE SEI Reports Third-Quarter 2021 Financial Results OAKS, Pa., Oct. 20, 2021 ? SEI Investments Company (NASDAQ:SEIC) today announced financial results for the third-quarter 2021. Diluted earnings per share were $0.97 in thi

July 26, 2021 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ? QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2021 or ? TRANSITION REPORT PURSUANT TO SECTION 13 OF 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period fromto Commission File Number: 0-10200 SEI INVESTMENTS COMPANY

July 21, 2021 EX-99.1

SEI Reports Second-Quarter 2021 Financial Results

Exhibit 99.1 Investor Contact: Media Contact: Lindsey Opsahl Leslie Wojcik SEI SEI +1 610-676-4052 +1 610-676-4191 [email protected] [email protected] Pages: 8 FOR IMMEDIATE RELEASE SEI Reports Second-Quarter 2021 Financial Results OAKS, Pa., July 21, 2021 ? SEI Investments Company (NASDAQ:SEIC) today announced financial results for the second-quarter 2021. Diluted earnings per share were $0.93 in s

July 21, 2021 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 July 21, 2021 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission File

June 28, 2021 11-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K (Mark One) x ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2020 ¨ TRANSITION REPORT PURSUANT TO

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K (Mark One) x ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2020 OR ? TRANSITION REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file Number 0-10200 A. Full title of the plan and

June 3, 2021 EX-99.1

SEI Declares Dividend of $0.37 Per Share Company Increases Share Repurchase Program by $250 million

Exhibit 99.1 Company Contact: Leslie Wojcik SEI +1 610-676-4191 [email protected] Pages: 1 FOR IMMEDIATE RELEASE SEI Declares Dividend of $0.37 Per Share Company Increases Share Repurchase Program by $250 million OAKS, Pa., June 2, 2021 ? The Board of Directors of SEI Investments Company (NASDAQ: SEIC) on June 2, 2021 declared a dividend of $0.37 (thirty-seven cents) per share. The cash dividend wi

June 3, 2021 8-K

Financial Statements and Exhibits, Other Events, Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 June 2, 2021 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in its charter) Pennsylvania 0-10200 23-1707341 (State or other jurisdiction of incorporation) (Commission F

April 27, 2021 DEF 14A

- DEFINITIVE PROXY STATEMENT

SCHEDULE 14A INFORMATION PROXY STATEMENT PURSUANT TO SECTION 14(A) OF THE SECURITIES EXCHANGE ACT OF 1934 Filed by the Registrant x Filed by a Party other than the Registrant ? Check the appropriate box: ? Preliminary Proxy Statement ? CONFIDENTIAL, FOR USE OF THE COMMISSION ONLY (AS PERMITTED BY RULE 14A-6(E)(2)) x Definitive Proxy Statement ? Definitive Additional Materials ? Soliciting Material Pursuant to Rule 14a-12 SEI INVESTMENTS COMPANY (Name of Registrant as Specified in Its Charter) N/A (Name of Person(s) Filing Proxy Statement, if other than the Registrant) Payment of Filing Fee (Check the appropriate box): x No fee required.

April 26, 2021 EX-10.27

Credit Agreement, dated as of April 23, 2021 among SEI Investments Company, the Lenders, U.S. Bank National Association, as Syndication Agent, Bank of America, N.A., Citizens Bank, N.A., Manufacturers and Traders Trust Company and Regions Bank, as Documentation Agents, and Wells Fargo Bank, National Association, as Administrative Agent (Incorporated by reference to exhibit 10.27 to the Registrant’s Quarterly Report on Form 10-Q for the quarterly period ended March 31, 2021.)

13802345v12 24740.00076 Exhibit 10.27 EXECUTION VERSION Published CUSIP Number: 78411SAJ6 Revolving Credit CUSIP Number: 78411SAK3 $325,000,000 CREDIT AGREEMENT dated as of April 23, 2021, by and among SEI INVESTMENTS COMPANY, as Borrower, the Lenders referred to herein, as Lenders, and WELLS FARGO BANK, NATIONAL ASSOCIATION, as Administrative Agent, Swingline Lender and Issuing Lender WELLS FARGO

April 26, 2021 10-Q

Quarterly Report - FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ? QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2021 or ? TRANSITION REPORT PURSUANT TO SECTION 13 OF 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period fromto Commission File Number: 0-10200 SEI INVESTMENTS COMPANY

April 21, 2021 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 April 21, 2021 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission Fil

April 21, 2021 EX-99.1

SEI Reports First-Quarter 2021 Financial Results

Exhibit 99.1 Investor Contact: Media Contact: Lindsey Opsahl Leslie Wojcik SEI SEI +1 610-676-4052 +1 610-676-4191 [email protected] [email protected] Pages: 8 FOR IMMEDIATE RELEASE SEI Reports First-Quarter 2021 Financial Results OAKS, Pa., April 21, 2021 ? SEI Investments Company (NASDAQ:SEIC) today announced financial results for the first-quarter 2021. Diluted earnings per share were $0.89 in fi

March 31, 2021 EX-99.1

Press Release of SEI Investments Company

Exhibit 99.1

March 31, 2021 8-K

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 March 29, 2021 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission Fil

March 4, 2021 EX-99.1

C O R P O R A T E S O C I A L R E S P O N S I B I L I T Y R E P O R T 2 0 1 9 2 0 1 9 C S R R E P O R T | S E I C .C O M | 1 Table of Contents Introduction Corporate Social Responsibility at SEI About the Report Governance and Ethics Ethics and Compl

a20087201-crpxcsrreport C O R P O R A T E S O C I A L R E S P O N S I B I L I T Y R E P O R T 2 0 1 9 2 0 1 9 C S R R E P O R T | S E I C .

March 4, 2021 8-K

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 March 4, 2021 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission File

February 22, 2021 10-K

Annual Report - FORM 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ? ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2020 OR ? TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period fromto Commission File Number: 0-10200 SEI INVESTMENTS COMPANY (Exa

February 22, 2021 EX-99.11

Financial Statements of LSV Asset Management dated December 31, 2020 and 2019. (Incorporated by reference to exhibit 99.11 to the Registrant's Annual Report on Form 10-K for the fiscal year ended December 31, 2020.)

EXHIBIT 99.11 LSV Asset Management Financial Statements As of December 31, 2020 and 2019 and for the years in the three-year period ended December 31, 2020 LSV Asset Management Table of Contents December 31, 2020 Page Independent Auditors' Report 3 Financial Statements Balance Sheets 4 Statements of Operations 5 Statements of Changes in Partners' Capital 6 Statements of Cash Flows 7 Notes to Finan

February 22, 2021 EX-21

Subsidiaries of the Registrant.

EXHIBIT 21 SUBSIDIARIES OF THE REGISTRANT NAME JURISDICTION OF ORGANIZATION OR INCORPORATION SEI Investments Distribution Co.

February 10, 2021 SC 13G/A

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No.: 7)*

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No.: 7)* Name of issuer: SEI Investments Co. Title of Class of Securities: Common Stock CUSIP Number: 784117103 Date of Event Which Requires Filing of this Statement: December 31, 2020 Check the appropriate box to designate the rule pursuant to which this Schedule is filed: ☒

January 28, 2021 EX-99.1

SEI Reports Fourth-Quarter 2020 Financial Results

Exhibit 99.1 Investor Contact: Media Contact: Lindsey Opsahl Leslie Wojcik SEI SEI +1 610-676-4052 +1 610-676-4191 [email protected] [email protected] Pages: 8 FOR IMMEDIATE RELEASE SEI Reports Fourth-Quarter 2020 Financial Results OAKS, Pa., Jan. 27, 2021 – SEI Investments Company (NASDAQ:SEIC) today announced financial results for the fourth-quarter 2020. Diluted earnings per share were $0.86 in f

January 28, 2021 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition - FORM 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 January 27, 2021 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission F

December 9, 2020 EX-99.1

SEI Declares Dividend of $0.37 per Share

Exhibit 99.1 Investor Contact: Leslie Wojcik SEI +1 610-676-4191 [email protected] Pages: 1 FOR IMMEDIATE RELEASE SEI Declares Dividend of $0.37 per Share OAKS, Pa., Dec. 8, 2020 – The Board of Directors of SEI Investments Company (NASDAQ: SEIC) on Dec. 8, 2020 declared a regular semi-annual dividend of $0.37 (thirty-seven cents) per share. The cash dividend will be payable to shareholders of recor

December 9, 2020 8-K

Financial Statements and Exhibits, Other Events - FORM 8-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 December 8, 2020 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in its charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commissi

October 26, 2020 10-Q

Quarterly Report - FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2020 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OF 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period fromto Commission File Number: 0-10200 SEI INVESTMENTS COM

October 26, 2020 EX-99.1

Press release dated October 21, 2020 of SEI Investments Company related to the Company's financial and operating results for the third quarter ended September 30, 2020.

Exhibit 99.1 Investor Contact: Media Contact: Lindsey Opsahl Leslie Wojcik SEI SEI +1 610-676-4052 +1 610-676-4191 [email protected] [email protected] Pages: 8 FOR IMMEDIATE RELEASE SEI Reports Third-Quarter 2020 Financial Results OAKS, Pa., Oct. 21, 2020 – SEI Investments Company (NASDAQ:SEIC) today announced financial results for the third-quarter 2020. Diluted earnings per share were $0.75 in thi

August 5, 2020 8-K

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 August 5, 2020 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission Fil

July 28, 2020 10-Q

Quarterly Report - FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2020 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OF 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period fromto Commission File Number: 0-10200 SEI INVESTMENTS COMPANY

July 28, 2020 EX-99.1

Press release dated July 22, 2020 of SEI Investments Company related to the Company's financial and operating results for the second quarter ended June 30, 2020.

Exhibit 99.1 Investor Contact: Media Contact: Lindsey Opsahl Leslie Wojcik SEI SEI +1 610-676-4052 +1 610-676-4191 [email protected] [email protected] Pages: 8 FOR IMMEDIATE RELEASE SEI Reports Second-Quarter 2020 Financial Results OAKS, Pa., July 22, 2020 – SEI Investments Company (NASDAQ:SEIC) today announced financial results for the second-quarter 2020. Diluted earnings per share were $0.68 in s

June 19, 2020 11-K

- FORM 11-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K (Mark One) x ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2019 OR ¨ TRANSITION REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file Number 0-10200 A. Full title of the plan and

June 4, 2020 EX-99.1

SEI Declares Dividend of $0.35 Per Share

Exhibit 99.1 Company Contact: Leslie Wojcik SEI +1 610-676-4191 [email protected] Pages: 1 FOR IMMEDIATE RELEASE SEI Declares Dividend of $0.35 Per Share OAKS, Pa., June 3, 2020 – The Board of Directors of SEI Investments Company (NASDAQ: SEIC) on June 3, 2020 declared a dividend of $0.35 (thirty-five cents) per share. The cash dividend will be payable to shareholders of record on June 15, 2020 wit

June 4, 2020 8-K

Financial Statements and Exhibits, Other Events, Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 June 3, 2020 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in its charter) Pennsylvania 0-10200 23-1707341 (State or other jurisdiction of incorporation) (Commission F

May 14, 2020 DEFA14A

- ADDITIONAL DEFINITIVE PROXY SOLICITING MATERIALS

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, DC 20549 SCHEDULE 14A INFORMATION PROXY STATEMENT PURSUANT TO SECTION 14(A) OF THE SECURITIES EXCHANGE ACT OF 1934 (Amendment No.

April 28, 2020 EX-99.1

Press release dated April 23, 2020 of SEI Investments Company related to the Company's financial and operating results for the first quarter ended March 31, 2020.

Exhibit 99.1 Investor Contact: Media Contact: Lindsey Opsahl Leslie Wojcik SEI SEI +1 610-676-4052 +1 610-676-4191 [email protected] [email protected] Pages: 8 FOR IMMEDIATE RELEASE SEI Reports First-Quarter 2020 Financial Results OAKS, Pa., April 23, 2020 – SEI Investments Company (NASDAQ:SEIC) today announced financial results for the first-quarter 2020. Diluted earnings per share were $0.72 in fi

April 28, 2020 10-Q

Quarterly Report - FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2020 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OF 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period fromto Commission File Number: 0-10200 SEI INVESTMENTS COMPANY

April 23, 2020 DEF 14A

- DEFINITIVE PROXY STATEMENT

SCHEDULE 14A INFORMATION PROXY STATEMENT PURSUANT TO SECTION 14(A) OF THE SECURITIES EXCHANGE ACT OF 1934 Filed by the Registrant x Filed by a Party other than the Registrant ¨ Check the appropriate box: ¨ Preliminary Proxy Statement ¨ CONFIDENTIAL, FOR USE OF THE COMMISSION ONLY (AS PERMITTED BY RULE 14A-6(E)(2)) x Definitive Proxy Statement ¨ Definitive Additional Materials ¨ Soliciting Material Pursuant to Rule 14a-12 SEI INVESTMENTS COMPANY (Name of Registrant as Specified in Its Charter) N/A (Name of Person(s) Filing Proxy Statement, if other than the Registrant) Payment of Filing Fee (Check the appropriate box): x No fee required.

March 18, 2020 8-K

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 March 18, 2020 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in its charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission

March 18, 2020 EX-99.1

SEI Announces Increase in Stock Repurchase Program

Exhibit 99.1 Investor Contact: Media Contact: Lindsey Opsahl Leslie Wojcik SEI SEI +1 610-676-4052 +1 610-676-4191 [email protected] [email protected] Pages: 1 FOR IMMEDIATE RELEASE SEI Announces Increase in Stock Repurchase Program OAKS, Pa., March 18, 2020 - The Board of Directors of SEI Investments Company (NASDAQ: SEIC) today announced an increase in its stock repurchase program by an additional

February 24, 2020 EX-99.10

Financial Statements of LSV Asset Management dated December 31, 2019 and 2018. (Incorporated by reference to exhibit 99.10 to the Registrant's Annual Report on Form 10-K for the fiscal year ended December 31, 2019.)

EXHIBIT 99.10 LSV Asset Management Financial Statements As of December 31, 2019 and 2018 and for the years in the three-year period ended December 31, 2019 LSV Asset Management Table of Contents December 31, 2019 Page Independent Auditors' Report 3 Financial Statements Balance Sheets 4 Statements of Operations 5 Statements of Changes in Partners' Capital 6 Statements of Cash Flows 7 Notes to Finan

February 24, 2020 10-K

Annual Report - FORM 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K ☒ ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2019 OR ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period fromto Commission File Number: 0-10200 SEI INVESTMENTS COMPANY (Exa

February 24, 2020 EX-21

Subsidiaries of the Registrant.

EXHIBIT 21 SUBSIDIARIES OF THE REGISTRANT NAME JURISDICTION OF ORGANIZATION OR INCORPORATION SEI Investments Distribution Co.

February 12, 2020 SC 13G/A

SEIC / SEI Investments Co. / VANGUARD GROUP INC - SCHEDULE 13G/A Passive Investment

SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No.: 6)* Name of issuer: SEI Investments Co Title of Class of Securities: Common Stock CUSIP Number: 784117103 Date of Event Which Requires Filing of this Statement: December 31, 2019 Check the appropriate box to designate the rule pursuant to which this Schedule is filed: ☒ 

January 29, 2020 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 January 29, 2020 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commission F

January 29, 2020 EX-99.1

SEI Reports Fourth-Quarter 2019 Financial Results

Exhibit 99.1 Investor Contact: Media Contact: Lindsey Opsahl Leslie Wojcik SEI SEI +1 610-676-4052 +1 610-676-4191 [email protected] [email protected] Pages: 8 FOR IMMEDIATE RELEASE SEI Reports Fourth-Quarter 2019 Financial Results OAKS, Pa., Jan. 29, 2020 – SEI Investments Company (NASDAQ:SEIC) today announced financial results for the fourth-quarter 2019. Diluted earnings per share were $0.84 in f

December 10, 2019 EX-99.1

SEI Declares Dividend of $0.35 Per Share

Exhibit 99.1 Investor Contact: Leslie Wojcik SEI +1 610-676-4191 [email protected] Pages: 1 FOR IMMEDIATE RELEASE SEI Declares Dividend of $0.35 Per Share OAKS, Pa., Dec. 10, 2019 – The Board of Directors of SEI Investments Company (NASDAQ: SEIC) on Dec. 9, 2019 declared a regular semi-annual dividend of $0.35 (thirty-five cents) per share. The cash dividend will be payable to shareholders of recor

December 10, 2019 8-K

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT PURSUANT TO SECTION 13 OR 15(D) OF THE SECURITIES EXCHANGE ACT OF 1934 December 9, 2019 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in its charter) Pennsylvania 0-10200 23-1707341 (State or Other Jurisdiction of Incorporation) (Commissi

October 24, 2019 EX-99.1

Press release dated October 23, 2019 of SEI Investments Company related to the Company's financial and operating results for the third quarter ended September 30, 2019.

Exhibit 99.1 Investor Contact: Media Contact: Lindsey Opsahl Leslie Wojcik SEI SEI +1 610-676-4052 +1 610-676-4191 [email protected] [email protected] Pages: 7 FOR IMMEDIATE RELEASE SEI Reports Third-Quarter 2019 Financial Results Company Hits $1 Trillion in Combined Assets under Management, Administration and Advisement OAKS, Pa., Oct. 23, 2019 – SEI Investments Company (NASDAQ:SEIC) today announce

October 24, 2019 10-Q

Quarterly Report - FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended September 30, 2019 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OF 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period fromto Commission File Number: 0-10200 SEI INVESTMENTS COM

July 25, 2019 10-Q

Quarterly Report - FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ☒ QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended June 30, 2019 or ☐ TRANSITION REPORT PURSUANT TO SECTION 13 OF 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period fromto Commission File Number: 0-10200 SEI INVESTMENTS COMPANY

July 25, 2019 EX-99.1

Press release dated July 24, 2019 of SEI Investments Company related to the Company's financial and operating results for the second quarter ended June 30, 2019.

Exhibit 99.1 Investor Contact: Media Contact: Lindsey Opsahl Leslie Wojcik SEI SEI +1 610-676-4052 +1 610-676-4191 [email protected] [email protected] Pages: 8 FOR IMMEDIATE RELEASE SEI Reports Second-Quarter 2019 Financial Results OAKS, Pa., July 24, 2019 – SEI Investments Company (NASDAQ:SEIC) today announced financial results for the second-quarter 2019. Diluted earnings per share were $0.82 in s

June 21, 2019 11-K

SEIC / SEI Investments Co. 11-K - - FORM 11-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 11-K (Mark One) x ANNUAL REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2018 OR ¨ TRANSITION REPORT PURSUANT TO SECTION 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission file Number 0-10200 A. Full title of the plan and

May 31, 2019 EX-99.1

SEI Declares Dividend of $0.33 Per Share

Exhibit 99.1 Company Contact: Lindsey Opsahl SEI +1 610-676-4052 [email protected] Pages: 1 FOR IMMEDIATE RELEASE SEI Declares Dividend of $0.33 Per Share OAKS, Pa., May 29, 2019 - The Board of Directors of SEI Investments Company (NASDAQ: SEIC) today declared a regular semi-annual dividend of $0.33 (thirty-three cents) per share. The cash dividend will be payable to shareholders of record on June

May 31, 2019 8-K

Financial Statements and Exhibits, Other Events, Submission of Matters to a Vote of Security Holders

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 May 29, 2019 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in its charter) Pennsylvania 0-10200 23-1707341 (State or other jurisdiction of incorporation) (Commission F

April 25, 2019 EX-99.1

Press release dated April 24, 2019 of SEI Investments Company related to the Company's financial and operating results for the first quarter ended March 31, 2019.

Exhibit 99.1 Investor Contact: Media Contact: Lindsey Opsahl Leslie Wojcik SEI SEI +1 610-676-4052 +1 610-676-4191 [email protected] [email protected] Pages: 8 FOR IMMEDIATE RELEASE SEI Reports First-Quarter 2019 Financial Results OAKS, Pa., April 24, 2019 – SEI Investments Company (NASDAQ:SEIC) today announced financial results for the first-quarter 2019. Diluted earnings per share were $0.73 in fi

April 25, 2019 10-Q

Quarterly Report - FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q ý QUARTERLY REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the quarterly period ended March 31, 2019 or ¨ TRANSITION REPORT PURSUANT TO SECTION 13 OF 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period from to Commission File Number: 0-10200 SEI INVESTMENTS COMPAN

April 17, 2019 DEF 14A

SEIC / SEI Investments Co. DEFINITIVE PROXY STATEMENT

SCHEDULE 14A INFORMATION PROXY STATEMENT PURSUANT TO SECTION 14(A) OF THE SECURITIES EXCHANGE ACT OF 1934 Filed by the Registrant ý Filed by a Party other than the Registrant ¨ Check the appropriate box: ¨ Preliminary Proxy Statement ¨ CONFIDENTIAL, FOR USE OF THE COMMISSION ONLY (AS PERMITTED BY RULE 14A-6(E)(2)) ý Definitive Proxy Statement ¨ Definitive Additional Materials ¨ Soliciting Material Pursuant to Rule 14a-12 SEI INVESTMENTS COMPANY (Name of Registrant as Specified in Its Charter) N/A (Name of Person(s) Filing Proxy Statement, if other than the Registrant) Payment of Filing Fee (Check the appropriate box): ý No fee required.

February 25, 2019 EX-10.12

Employment Agreement, dated May 2, 2018, between Michael N. Peterson and the Registrant. (Incorporated by reference to exhibit 10.12 to the Registrant's Annual Report on Form 10-K for the fiscal year ended December 31, 2018.)

EXHIBIT 10.12 SEI INVESTMENTS COMPANY May 2, 2018 Michael Peterson [Residence Address Omitted] Dear Michael: On behalf of SEI, we are pleased to extend this offer of employment to you to perform the role of Executive Vice President and General Counsel. In this role, you will be responsible for the leadership of the legal and compliance functions, and provide counsel to the Board of Directors and i

February 25, 2019 EX-21

Subsidiaries of the Registrant.

EXHIBIT 21 SUBSIDIARIES OF THE REGISTRANT NAME JURISDICTION OF ORGANIZATION OR INCORPORATION SEI Investments Distribution Co.

February 25, 2019 10-K

Annual Report - FORM 10-K

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-K (Mark One) ý ANNUAL REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the fiscal year ended December 31, 2018 OR ¨ TRANSITION REPORT PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934 For the transition period fromto Commission File Number: 0-10200 SEI INVESTMENTS C

February 25, 2019 EX-99.9

Financial Statements of LSV Asset Management dated December 31, 2018 and 2017. (Incorporated by reference to exhibit 99.9 to the Registrant's Annual Report on Form 10-K for the fiscal year ended December 31, 2018.)

EXHIBIT 99.9 LSV Asset Management Financial Statements As of December 31, 2018 and 2017 and for each of the three years in the period ended December 31, 2018 LSV Asset Management Table of Contents December 31, 2018 Page Independent Auditors' Report 1 Financial Statements Balance Sheets 2 Statements of Operations 3 Statements of Changes in Partners' Capital 4 Statements of Cash Flows 5 Notes to Fin

February 13, 2019 SC 13G/A

SEIC / SEI Investments Co. / VANGUARD GROUP INC Passive Investment

seiinvestmentsco.htm - Generated by SEC Publisher for SEC Filing SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Schedule 13G Under the Securities Exchange Act of 1934 (Amendment No.: 5 )* Name of issuer: SEI Investments Co Title of Class of Securities: Common Stock CUSIP Number: 784117103 Date of Event Which Requires Filing of this Statement: December 31, 2018 Check the appropriate box

January 30, 2019 EX-99.1

SEI Reports Fourth-Quarter 2018 Financial Results

Exhibit 99.1 Investor Contact: Media Contact: Lindsey Opsahl Leslie Wojcik SEI SEI +1 610-676-4052 +1 610-676-4191 [email protected] [email protected] Pages: 8 FOR IMMEDIATE RELEASE SEI Reports Fourth-Quarter 2018 Financial Results OAKS, Pa., Jan. 30, 2019 – SEI Investments Company (NASDAQ:SEIC) today announced financial results for the fourth-quarter 2018. Diluted earnings per share were $0.73 in f

January 30, 2019 8-K

Financial Statements and Exhibits, Results of Operations and Financial Condition

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 January 30, 2019 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in its charter) Pennsylvania 0-10200 23-1707341 (State or other jurisdiction of incorporation) (Commissi

December 11, 2018 EX-99.1

SEI Declares Dividend of $0.33 Per Share and Announces Increase in Stock Repurchase Program

Exhibit 99.1 Investor Contact: Lindsey Opsahl SEI +1 610-676-4052 [email protected] Pages: 1 FOR IMMEDIATE RELEASE SEI Declares Dividend of $0.33 Per Share and Announces Increase in Stock Repurchase Program OAKS, Pa., Dec. 11, 2018 – The Board of Directors of SEI Investments Company (NASDAQ: SEIC) today declared a regular semi-annual dividend of $0.33 (thirty-three cents) per share. The cash divide

December 11, 2018 8-K

Financial Statements and Exhibits, Other Events

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 December 11, 2018 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in its charter) Pennsylvania 0-10200 23-1707341 (State or other jurisdiction of incorporation) (Commiss

November 14, 2018 8-K

Regulation FD Disclosure, Financial Statements and Exhibits

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 8-K CURRENT REPORT Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 November 14, 2018 Date of report (Date of earliest event reported) SEI INVESTMENTS COMPANY (Exact name of registrant as specified in its charter) Pennsylvania 0-10200 23-1707341 (State or other jurisdiction of incorporation) (Commiss

November 14, 2018 EX-99.1

SEI Positions Organization for Accelerated Growth Company’s Unified Processing and Technology Business to Support Markets’ Convergence

Exhibit 99.1 Company/Media Contact: Leslie Wojcik SEI +1 610-676-4191 [email protected] Pages: 2 FOR IMMEDIATE RELEASE SEI Positions Organization for Accelerated Growth Company’s Unified Processing and Technology Business to Support Markets’ Convergence OAKS, Pa., Nov. 14, 2018 - SEI (NASDAQ:SEIC) today announced changes to its executive leadership to better align the company’s organizational struc

October 25, 2018 10-Q

Quarterly Report - FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One)* ý Quarterly report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the quarterly period ended September 30, 2018 or ¨ Transition report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the transition period from to 0-10200 (Commission File Number) SEI I

October 25, 2018 EX-99.1

Press release dated October 23, 2018 of SEI Investments Company related to the Company's financial and operating results for the third quarter ended September 30, 2018.

Exhibit 99.1 Investor Contact: Media Contact: Lindsey Opsahl Leslie Wojcik SEI SEI +1 610-676-4052 +1 610-676-4191 [email protected] [email protected] Pages: 8 FOR IMMEDIATE RELEASE SEI Reports Third-Quarter 2018 Financial Results OAKS, Pa., Oct. 23, 2018 – SEI Investments Company (NASDAQ:SEIC) today announced financial results for the third-quarter 2018. Diluted earnings per share were $0.80 in thi

July 24, 2018 10-Q

Quarterly Report - FORM 10-Q

UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 FORM 10-Q (Mark One)* ý Quarterly report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the quarterly period ended June 30, 2018 or ¨ Transition report pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934 for the transition period from to 0-10200 (Commission File Number) SEI INVEST

July 24, 2018 EX-99.1

Press release dated July 19, 2018 of SEI Investments Company related to the Company's financial and operating results for the second quarter ended June 30, 2018.

Exhibit 99.1 Investor Contact: Media Contact: Lindsey Opsahl Leslie Wojcik SEI SEI +1 610-676-4052 +1 610-676-4191 [email protected] [email protected] Pages: 8 FOR IMMEDIATE RELEASE SEI Reports Second-Quarter 2018 Financial Results OAKS, Pa., July 19, 2018 – SEI Investments Company (NASDAQ:SEIC) today announced financial results for the second-quarter 2018. Diluted earnings per share were $0.75 in s

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