SEIC 13G/A: Loomis, Sayles Discloses 8.89M Shares and Voting Power

Rhea-AI Filing Summary

Loomis, Sayles & Co., L.P. reports beneficial ownership of 8,886,767.60 shares of SEI Investments common stock, equal to 7.14% of the class. The filing shows sole voting power over 7,233,424 shares while reporting no sole or shared dispositive power to direct the sale of the shares. The filer identifies itself as an investment adviser organized in Delaware and states that clients may have rights to dividends or sale proceeds, with no single client holding more than 5% of the class. The filing includes the required certification of accuracy.

Positive

• Material ownership disclosed: Loomis reports 8,886,767.60 shares, representing 7.14% of SEI's common stock.
• Significant voting influence: The filer reports sole voting power over 7,233,424 shares.
• Clear classification: Filer identifies as an investment adviser organized in Delaware and includes required certification.

Negative

• No dispositive power reported: The filing indicates 0 sole or shared dispositive power, suggesting limited ability to direct sale of shares.
• Potential ambiguity: Separation of voting power from dispositive power may complicate assessment of economic control and liquidity of the stake.

Insights

Financial Analyst

TL;DR: Loomis, Sayles disclosed a material 7.14% SEIC stake with concentrated voting control but reported no dispositive power.

The disclosure shows a meaningful economic interest at the 7% level, which is material for shareholder registers and index inclusion considerations. Notably, the firm reports sole voting power on 7.23 million shares while indicating no sole or shared dispositive power, an unusual alignment that suggests voting authority is separate from the right to sell. This can affect how market participants interpret Loomis influence on corporate votes versus its ability to liquidate holdings.

Corporate Governance Expert

TL;DR: Significant voting concentration reported without dispositive authority raises governance and disclosure questions.

The filing is material because it crosses the 5% threshold and documents concentrated voting control relative to economic disposition. From a governance perspective, having voting power without dispositive power may reflect client-directed voting arrangements or custodial structures; the filing notes clients hold dividend or sale rights but no single client exceeds 5%. This distinction is important for understanding who actually sets corporate policy through votes versus who bears economic risk.

SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

SCHEDULE 13G

UNDER THE SECURITIES EXCHANGE ACT OF 1934

(Amendment No. 15)

SEI Investments Co

(Name of Issuer)

Common Stock

(Title of Class of Securities)

784117103

(CUSIP Number)

06/30/2025

(Date of Event Which Requires Filing of this Statement)

Check the appropriate box to designate the rule pursuant to which this Schedule is filed:

Rule 13d-1(b)

Rule 13d-1(c)

Rule 13d-1(d)

SCHEDULE 13G

CUSIP No. 784117103

1

Names of Reporting Persons

Loomis, Sayles & Co., L.P.

2

Check the appropriate box if a member of a Group (see instructions)

(a)
(b)

3

Sec Use Only

4

Citizenship or Place of Organization

DELAWARE

Number of Shares Beneficially Owned by Each Reporting Person With:

5	Sole Voting Power 7,233,424.00
6	Shared Voting Power 0.00
7	Sole Dispositive Power 0.00
8	Shared Dispositive Power 0.00

9

Aggregate Amount Beneficially Owned by Each Reporting Person

8,886,767.60

10

Check box if the aggregate amount in row (9) excludes certain shares (See Instructions)

11

Percent of class represented by amount in row (9)

7.14 %

12

Type of Reporting Person (See Instructions)

IA

SCHEDULE 13G

Item 1.
(a)	Name of issuer: SEI Investments Co
(b)	Address of issuer's principal executive offices: 1 FREEDOM VALLEY DRIVE, OAKS, PA, 19456-1100
Item 2.
(a)	Name of person filing: Loomis, Sayles & Co., L.P.
(b)	Address or principal business office or, if none, residence: One Financial Center Boston, MA 02111
(c)	Citizenship: United States
(d)	Title of class of securities: Common Stock
(e)	CUSIP No.: 784117103
Item 3.	If this statement is filed pursuant to §§ 240.13d-1(b) or 240.13d-2(b) or (c), check whether the person filing is a:
(a)	Broker or dealer registered under section 15 of the Act (15 U.S.C. 78o);
(b)	Bank as defined in section 3(a)(6) of the Act (15 U.S.C. 78c);
(c)	Insurance company as defined in section 3(a)(19) of the Act (15 U.S.C. 78c);
(d)	Investment company registered under section 8 of the Investment Company Act of 1940 (15 U.S.C. 80a-8);
(e)	An investment adviser in accordance with § 240.13d-1(b)(1)(ii)(E);
(f)	An employee benefit plan or endowment fund in accordance with § 240.13d-1(b)(1)(ii)(F);
(g)	A parent holding company or control person in accordance with § 240.13d-1(b)(1)(ii)(G);
(h)	A savings associations as defined in Section 3(b) of the Federal Deposit Insurance Act (12 U.S.C. 1813);
(i)	A church plan that is excluded from the definition of an investment company under section 3(c)(14) of the Investment Company Act of 1940 (15 U.S.C. 80a-3);
(j)	A non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J). If filing as a non-U.S. institution in accordance with § 240.13d-1(b)(1)(ii)(J), please specify the type of institution:
(k)	Group, in accordance with Rule 240.13d-1(b)(1)(ii)(K).
Item 4.	Ownership
(a)	Amount beneficially owned: 8886767.6
(b)	Percent of class: 7.14 %
(c)	Number of shares as to which the person has:
	(i) Sole power to vote or to direct the vote: 7233424.0
	(ii) Shared power to vote or to direct the vote: 0
	(iii) Sole power to dispose or to direct the disposition of: 0
	(iv) Shared power to dispose or to direct the disposition of: 0
Item 5.	Ownership of 5 Percent or Less of a Class.
Item 6.	Ownership of more than 5 Percent on Behalf of Another Person.
	If any other person is known to have the right to receive or the power to direct the receipt of dividends from, or the proceeds from the sale of, such securities, a statement to that effect should be included in response to this item and, if such interest relates to more than 5 percent of the class, such person should be identified. A listing of the shareholders of an investment company registered under the Investment Company Act of 1940 or the beneficiaries of employee benefit plan, pension fund or endowment fund is not required. Clients of Reporting Person have such a right, none of whom has such interest relating to more than 5% of any class.
Item 7.	Identification and Classification of the Subsidiary Which Acquired the Security Being Reported on by the Parent Holding Company or Control Person.
	Not Applicable
Item 8.	Identification and Classification of Members of the Group.
	Not Applicable
Item 9.	Notice of Dissolution of Group.
	Not Applicable

Item 10.

Certifications:

By signing below I certify that, to the best of my knowledge and belief, the securities referred to above were acquired andare held in the ordinary course of business and were not acquired and are not held for the purpose of or with the effect ofchanging or influencing the control of the issuer of the securities and were not acquired and are not held in connection withor as a participant in any transaction having that purpose or effect, other than activities solely in connection with anomination under 240.14a-11.

SIGNATURE

After reasonable inquiry and to the best of my knowledge and belief, I certify that the information set forth in this statement is true, complete and correct.

Loomis, Sayles & Co., L.P.

Signature:	Mari Shimokawa
Name/Title:	Deputy Chief Compliance Officer
Date:	08/12/2025

FAQ

How many SEIC shares does Loomis, Sayles report owning?

The filing states Loomis, Sayles beneficially owns 8,886,767.60 shares of SEI (SEIC) common stock.

What percentage of SEI (SEIC) does Loomis, Sayles own?

Loomis, Sayles reports ownership equal to 7.14% of the class.

How much voting power does Loomis, Sayles report for SEIC shares?

The filer reports sole voting power for 7,233,424 shares and 0 shared voting power.

Does Loomis, Sayles report dispositive power over the SEIC shares?

The filing indicates 0 sole dispositive power and 0 shared dispositive power to direct the disposition of the shares.

Is Loomis, Sayles acting on behalf of clients for these SEIC shares?

Yes. The filing notes clients of the reporting person have rights to dividends or sale proceeds, and no single client has an interest exceeding 5% of the class.