SEC Form 5

FORM 5		UNITED STATES SECURITIES AND EXCHANGE COMMISSION Washington, D.C. 20549 ANNUAL STATEMENT OF CHANGES IN BENEFICIAL OWNERSHIP Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934 or Section 30(h) of the Investment Company Act of 1940	OMB APPROVAL OMB Number: 3235-0362 Estimated average burden hours per response: 1.0
	Check this box if no longer subject to Section 16. Form 4 or Form 5 obligations may continue. See Instruction 1(b).
	Form 3 Holdings Reported.
	Form 4 Transactions Reported.

1. Name and Address of Reporting Person* WEST ALFRED P JR (Last) (First) (Middle) ONE FREEDOM VALLEY DRIVE (Street) OAKS PA 19456 (City) (State) (Zip)	2. Issuer Name and Ticker or Trading Symbol SEI INVESTMENTS CO [ SEIC ]	5. Relationship of Reporting Person(s) to Issuer (Check all applicable) X Director X 10% Owner Officer (give title below) Other (specify below)
	3. Statement for Issuer's Fiscal Year Ended (Month/Day/Year) 12/31/2009
	4. If Amendment, Date of Original Filed (Month/Day/Year)	6. Individual or Joint/Group Filing (Check Applicable Line) X Form filed by One Reporting Person Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Acquired, Disposed of, or Beneficially Owned
1. Title of Security (Instr. 3)	2. Transaction Date (Month/Day/Year)	2A. Deemed Execution Date, if any (Month/Day/Year)	3. Transaction Code (Instr. 8)	4. Securities Acquired (A) or Disposed Of (D) (Instr. 3, 4 and 5)			5. Amount of Securities Beneficially Owned at end of Issuer's Fiscal Year (Instr. 3 and 4)	6. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	7. Nature of Indirect Beneficial Ownership (Instr. 4)
				Amount	(A) or (D)	Price
Common Stock	12/04/2006		G5	236,492(1)	D	$0	16,229,990	D
Common Stock	01/22/2007		G5	29,006(2)	D	$0	16,200,984	D
Common Stock	02/08/2007		G5	94,938(3)	D	$0	16,106,046	D
Common Stock	12/04/2007		G5	2,252	D	$0	16,103,794	D
Common Stock	12/04/2007		G5	6,992	D	$0	16,096,802	D
Common Stock	12/10/2007		G5	192,006	D	$0	15,904,796	D
Common Stock	06/05/2008		G5	20,231	D	$0	15,884,565	D
Common Stock	12/11/2008		G5	13,200	D	$0	15,871,365	D
Common Stock	06/02/2009		G5	165,915	D	$0	15,705,450	D
Common Stock	07/27/2009		G5	13,809	D	$0	15,691,641	D
Common Stock	12/10/2009		G5	13,750	D	$0	15,677,891	D
Common Stock	12/10/2009		G5	163,664	D	$0	15,514,227(4)	D

Table II - Derivative Securities Acquired, Disposed of, or Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 3)	2. Conversion or Exercise Price of Derivative Security	3. Transaction Date (Month/Day/Year)	3A. Deemed Execution Date, if any (Month/Day/Year)	4. Transaction Code (Instr. 8)	5. Number of Derivative Securities Acquired (A) or Disposed of (D) (Instr. 3, 4 and 5)		6. Date Exercisable and Expiration Date (Month/Day/Year)		7. Title and Amount of Securities Underlying Derivative Security (Instr. 3 and 4)		8. Price of Derivative Security (Instr. 5)	9. Number of derivative Securities Beneficially Owned Following Reported Transaction(s) (Instr. 4)	10. Ownership Form: Direct (D) or Indirect (I) (Instr. 4)	11. Nature of Indirect Beneficial Ownership (Instr. 4)
					(A)	(D)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares

Explanation of Responses:

1. The reporting person gifted a total of 118,246 shares of common stock of SEI Investments Company ("SEI") on December 4, 2006. SEI subsequently approved a two-for-one split of its outstanding common stock effective as of June 8, 2007. As a result, this gift is reported on this Form 5 as a gift of 236,492 shares, which is the post-split equivalent of the actual amount of gifted shares.

2. The reporting person gifted a total of 14,503 shares of common stock of SEI on January 22, 2007. SEI subsequently approved a two-for-one split of its outstanding common stock effective as of June 8, 2007. As a result, this gift is reported on this Form 5 as a gift of 29,006 shares, which is the post-split equivalent of the actual amount of gifted shares.

3. The reporting person gifted a total of 47,469 shares of common stock of SEI on February 8, 2007. SEI subsequently approved a two-for-one split of its outstanding common stock effective as of June 8, 2007. As a result, this gift is reported on this Form 5 as a gift of 94,938 shares, which is the post-split equivalent of the actual amount of gifted shares.

4. Reflects the total number of shares owned by the reporting person taking into account the following: (i) the gifts of 952,255 shares, in aggregate, reported on this Form 5, (ii) 4,714 shares inadvertently over-reported by the reporting person on a form 4 originally filed on 9/13/2007 and amended on the date of this report (iii) 30,090 shares inadvertently over-reported by the reporting person on a form 4 originally filed on 8/5/2008 and amended on the date of this report, (iv) 258,794 shares inadvertently over-reported by the reporting person on a form 4 originally filed on 5/8/2009 and amended on the date of this report, (v) 728 shares inadvertently over-reported by the reporting person on a form 4 originally filed on 6/22/2009 and amended on the date of this report, and (vi) 48 shares previously inadvertently reported as being directly owned by the reporting person.

Remarks:

	Ruth Montgomery (Attorney in Fact)	04/09/2010
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 4 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
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