SEI Investments officer plans $4.2M stock sale

SEI INVESTMENTS CO (SEIC) received a notice that officer Michael Peterson intends to sell shares of its common stock under Rule 144.

Rhea-AI Filing Summary

SEI INVESTMENTS CO (SEIC) received a notice that officer Michael Peterson intends to sell shares of its common stock under Rule 144. The planned transaction covers 37,500 shares, to be executed through Charles Schwab in connection with an employee stock option exercise via a broker-assisted cashless exercise on 08/28/2026.

The notice also reports that during the prior three months, Peterson sold 25,000 shares of SEI Investments common stock on 07/28/2026 for total proceeds of $2,551,125.00.

Key Figures

Shares proposed to be sold: 37,500 shares Aggregate market value of proposed sale: $4,181,773.00 Shares sold in prior 3 months: 25,000 shares +2 more

5 metrics

Shares proposed to be sold 37,500 shares Common stock sale under Rule 144, proposed 08/28/2026

Aggregate market value of proposed sale $4,181,773.00 Value of 37,500 SEI Investments common shares to be sold

Shares sold in prior 3 months 25,000 shares Sale by Michael Peterson on 07/28/2026

Proceeds from prior 3‑month sale $2,551,125.00 Total consideration for 25,000 shares sold on 07/28/2026

Proposed sale date 08/28/2026 Date listed for the Rule 144 sale and option exercise

Key Terms

Rule 144, Form 144, Employee Stock Option Exercise, cashless exercise

4 terms

Rule 144 regulatory

"See the definition of "person" in paragraph (a) of Rule 144."

Rule 144 is a U.S. securities regulation that sets conditions under which restricted or insider-held shares can be legally resold to the public, such as required holding periods, availability of public information, limits on how much can be sold at once, and certain filing requirements. For investors it matters because it determines when previously locked-up shares can enter the market — like a release valve that can increase supply, affect share price, and signal insider intent.

Form 144 regulatory

"144: Filer Information"

Form 144 is a document that investors must file with the government when they plan to sell a large number of shares of a company's stock. It helps ensure transparency so everyone knows how many shares are being sold and when, which can impact the stock's price.

Employee Stock Option Exercise financial

"Common | 08/28/2026 | Employee Stock Option Exercise | SEI INVESTMENTS CO"

cashless exercise financial

"Broker Payment for Cashless Exercise"

A cashless exercise is a way for an option holder to convert stock options into actual shares without paying the purchase price in cash; instead they immediately give up a portion of the newly issued shares to cover the cost and any withholding taxes. Investors care because this process increases the number of shares available and can slightly dilute existing holdings, while also signaling how insiders or employees are realizing compensation without needing cash — similar to paying for a purchase by handing over part of what you just bought.

FAQ

AI-generated questions and answers. How Rhea-AI works. Not financial advice.

What does the Form 144 filing disclose for SEIC?

The filing discloses that officer Michael Peterson plans to sell 37,500 shares of SEI Investments common stock under Rule 144 on or about 08/28/2026, in connection with an employee stock option exercise using a broker-assisted cashless exercise.

How many SEIC shares are proposed to be sold under this Form 144?

The notice states an intention to sell 37,500 shares of SEI Investments common stock. The planned sale is associated with an employee stock option exercise and will be handled through Charles Schwab & Co., Inc.

What is the aggregate market value of the SEIC shares in the planned sale?

The proposed sale of 37,500 shares of SEI Investments common stock has an aggregate market value of $4,181,773.00, based on the market price information provided in the notice.

Were there recent sales of SEIC shares by Michael Peterson before this notice?

Yes. The filing reports that on 07/28/2026, Michael Peterson sold 25,000 shares of SEI Investments common stock for total proceeds of $2,551,125.00 during the prior three months.

How will the SEIC shares be sold according to the Form 144?

The shares are expected to be sold through Charles Schwab & Co., Inc. as part of a broker payment for cashless exercise of employee stock options, with the proposed sale date listed as 08/28/2026.

AI-generated analysis. How Rhea-AI works. Not financial advice.

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Available on EDGAR 08/28/2026 - 04:28 PM EDT Accepted by SEC EDGAR 08/28/2026 - 04:27 PM EDT Learn about SEC filing dates

Form 144 Filer Information	UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 Form 144 NOTICE OF PROPOSED SALE OF SECURITIES PURSUANT TO RULE 144 UNDER THE SECURITIES ACT OF 1933
FORM 144

144: Filer Information

Filer CIK	0001745371
Filer CCC	XXXXXXXX
Is this a LIVE or TEST Filing?	LIVE TEST
Submission Contact Information
Name
Phone
E-Mail Address

144: Issuer Information

Name of Issuer	SEI INVESTMENTS CO
SEC File Number	000-10200
Address of Issuer	1 FREEDOM VALLEY DRIVE OAKS PENNSYLVANIA 19456-1100
Phone	6106761000
Name of Person for Whose Account the Securities are To Be Sold	Peterson Michael
See the definition of "person" in paragraph (a) of Rule 144. Information is to be given not only as to the person for whose account the securities are to be sold but also as to all other persons included in that definition. In addition, information shall be given as to sales by all persons whose sales are required by paragraph (e) of Rule 144 to be aggregated with sales for the account of the person filing this notice.
Relationship to Issuer	Officer

144: Securities Information

Title of the Class of Securities To Be Sold	Name and Address of the Broker	Number of Shares or Other Units To Be Sold	Aggregate Market Value	Number of Shares or Other Units Outstanding	Approximate Date of Sale	Name the Securities Exchange
Common	Charles Schwab & Co., Inc. 3000 Schwab Way Westlake TX 76262	37500	4181773.00	120019182	08/28/2026	NASDAQ

Furnish the following information with respect to the acquisition of the securities to be sold and with respect to the payment of all or any part of the purchase price or other consideration therefor:

144: Securities To Be Sold

Title of the Class	Date you Acquired	Nature of Acquisition Transaction	Name of Person from Whom Acquired	Is this a Gift?	Date Donor Acquired	Amount of Securities Acquired	Date of Payment	Nature of Payment *
Common	08/28/2026	Employee Stock Option Exercise	SEI INVESTMENTS CO			37500	08/28/2026	Broker Payment for Cashless Exercise

* If the securities were purchased and full payment therefor was not made in cash at the time of purchase, explain in the table or in a note thereto the nature of the consideration given. If the consideration consisted of any note or other obligation, or if payment was made in installments describe the arrangement and state when the note or other obligation was discharged in full or the last installment paid.

Furnish the following information as to all securities of the issuer sold during the past 3 months by the person for whose account the securities are to be sold.

144: Securities Sold During The Past 3 Months

Name and Address of Seller	Title of Securities Sold	Date of Sale	Amount of Securities Sold	Gross Proceeds
MICHAEL PETERSON 1 FREEDOM VALLEY DRIVE OAKS PA 19456-1100	SEI INVESTMENTS CO	07/28/2026	25000	2551125.00

144: Remarks and Signature

Remarks
Date of Notice	08/28/2026
ATTENTION:
The person for whose account the securities to which this notice relates are to be sold hereby represents by signing this notice that he does not know any material adverse information in regard to the current and prospective operations of the Issuer of the securities to be sold which has not been publicly disclosed. If such person has adopted a written trading plan or given trading instructions to satisfy Rule 10b5-1 under the Exchange Act, by signing the form and indicating the date that the plan was adopted or the instruction given, that person makes such representation as of the plan adoption or instruction date.
Signature	MICHAEL PETERSON
ATTENTION: Intentional misstatements or omission of facts constitute Federal Criminal Violations (See 18 U.S.C. 1001)