Exhibit 99.1

Investor Contact: Media Contact:

Lindsey Opsahl                        Leslie Wojcik

SEI                                    SEI

+1 610-676-4052                        +1 610-676-4191

lopsahl@seic.com lwojcik@seic.com

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 third-quarter 2020 compared to $0.86 in third-quarter 2019. On Tuesday, Oct. 20, 2020 the Board of Directors of SEI Investments Company approved an increase in its stock repurchase program by an additional $250 million, increasing the available authorization under the program to approximately $292 million.

Consolidated Overview
(In thousands, except earnings per share)						For the Three Months Ended September 30,																								For the Nine Months Ended September 30,
						2020						2019						%						2020						2019						%
Revenues						$424,927						$416,254						2%						$1,240,335						$1,226,660						1%
Net income						111,096						132,168						(16)%						321,404						372,689						(14)%
Diluted earnings per share						$0.75						$0.86						(13)%						$2.14						$2.40						(11)%

“The pandemic continues, as does our focus on clients and our employees’ health and safety. We are fortunate to have a strong global workforce that is resilient, engaged and dedicated to providing our clients best-in-class service, and committed to our company’s growth. Words can’t express our appreciation for their efforts, along with all of the healthcare and service providers who look after our health and well-being,” said Alfred P. West, Jr., SEI Chairman and CEO.

“Our business continued to rebound during the quarter, as our markets adjusted to the current environment. Our financial results reflect our strong sales activity, while we invest in our strategic priorities. Our diverse and talented global workforce drives our ability to serve our clients and make an impact on our communities. Looking to the future, we will capitalize on the opportunities in our markets to deliver long-term value to our shareholders, employees and clients.”

Summary of Third-Quarter Results by Business Segment

						For the Three Months Ended September 30,																								For the Nine Months Ended September 30,
(In thousands)
						2020						2019						%						2020						2019						%
Private Banks:
Revenues						$114,792						$117,250						(2)%						$335,739						$351,601						(5)%
Expenses						113,066						110,788						2%						331,442						329,540						1%
Operating Profit						1,726						6,462						(73)%						4,297						22,061						(81)%
Operating Margin						2		%				6		%										1		%				6		%
Investment Advisors:
Revenues						103,189						103,033						—%						299,218						297,916						—%
Expenses						51,519						51,509						—%						154,100						154,569						—%
Operating Profit						51,670						51,524						—%						145,118						143,347						1%
Operating Margin						50		%				50		%										48		%				48		%
Institutional Investors:
Revenues						79,583						80,337						(1)%						235,309						241,559						(3)%
Expenses						37,812						37,268						1%						113,016						115,383						(2)%
Operating Profit						41,771						43,069						(3)%						122,293						126,176						(3)%
Operating Margin						52		%				54		%										52		%				52		%
Investment Managers:
Revenues						123,846						112,186						10%						359,815						326,037						10%
Expenses						79,838						71,889						11%						228,795						209,326						9%
Operating Profit						44,008						40,297						9%						131,020						116,711						12%
Operating Margin						36		%				36		%										36		%				36		%
Investments in New Businesses:
Revenues						3,517						3,448						2%						10,254						9,547						7%
Expenses						13,315						7,926						68%						37,691						20,663						82%
Operating Loss						(9,798)						(4,478)						NM						(27,437)						(11,116)						NM
Totals:
Revenues						$424,927						$416,254						2%						$1,240,335						$1,226,660						1%
Expenses						295,550						279,380						6%						865,044						829,481						4%
Corporate Overhead Expenses						18,040						16,237						11%						53,414						52,845						1%
Income from Operations						$111,337						$120,637						(8)%						$321,877						$344,334						(7)%

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Third-Quarter Business Highlights:

•Revenues from Asset management, administration, and distribution fees increased primarily from higher assets under administration due to positive cash flows from new and existing clients in our Investment Managers segment.

•Our average assets under administration increased $84.8 billion, or 13%, to $738.8 billion in the third-quarter 2020, as compared to $654.0 billion during the third-quarter 2019 (see attached Average Asset Balances schedules for further details).

•Our average assets under management, excluding LSV, increased $13.1 billion, or 6%, to $246.1 billion in the third-quarter 2020, as compared to $233.0 billion during the third-quarter 2019 (see attached Average Asset Balances schedules for further details).

•Sales events, net of client losses, during third-quarter 2020 totaled approximately $27.9 million and are expected to generate net annualized recurring revenues of approximately $14.6 million when contract values are fully realized. For the nine months ended Sept. 30, 2020, sales events, net of client losses, totaled approximately $84.8 million and are expected to generate net annualized recurring revenues of approximately $63.5 million when contract values are fully realized.

•The increase in our operational expenses was primarily due to increased consulting costs related to our continued investments in new business opportunities, such as our One SEI strategy and IT Services offering, as well as increased personnel costs to service new clients in our Investment Managers segment. This increase was partially offset by a decline in travel and promotional-related expenses, as our sales and client relationship personnel adapted to COVID-19 restrictions.

•Our earnings from LSV decreased by $9.3 million, or 25%, to $28.3 million in third-quarter 2020, as compared to $37.6 million in third-quarter 2019. The decrease in earnings was due to lower assets under management from negative cash flows from existing clients, market depreciation and client losses.

•We capitalized $5.4 million of software development costs in third-quarter 2020 for continued enhancements to the SEI Wealth Platform^SM (SWP). Amortization expense related to SWP was $10.9 million in third-quarter 2020.

•Our effective tax rates were 21.4% in third-quarter 2020 and 18.9% in third-quarter 2019. The increase in our effective tax rate was due to decreased tax benefits associated with a lower volume of stock option exercises and a higher effective state tax rate.

•We repurchased 2.1 million shares of our common stock for $108.7 million during the third-quarter 2020.

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Earnings Conference Call

A conference call to review earnings is scheduled for 4:30 p.m. Eastern time on Oct. 21, 2020. Investors may listen to the call at seic.com/ir-events. Investors may also listen to a replay by telephone at (USA) 866-207-1041; (International) 402-970-0847; Access Code: 4259639.

About SEI

After 50 years in business, SEI (NASDAQ:SEIC) remains a leading global provider of investment processing, investment management, and investment operations solutions designed to help corporations, financial institutions, financial advisors, and ultra-high-net-worth families create and manage wealth. As of Sept. 30, 2020, through its subsidiaries and partnerships in which the company has a significant interest, SEI manages, advises or administers approximately $1 trillion in hedge, private equity, mutual fund and pooled or separately managed assets, including approximately $330 billion in assets under management and $755 billion in client assets under administration. For more information, visit seic.com.

This release contains forward-looking statements within the meaning or the rules and regulations of the Securities and Exchange Commission. In some cases you can identify forward-looking statements by terminology, such as ‘'may,’' '‘will,’' ‘'expect,’' ‘'believe’' and ‘'continue’' or ‘‘appear.’’ Our forward-looking statements include our current expectations as to:

• revenue that we believe will be generated by sales events that occurred during the quarter,

• the rebound of our business,

• whether and the degree to which we will invest in our strategic priorities, and

• whether capitalizing on the opportunities in our markets will deliver long-term value for any of our shareholders, employees or clients.

You should not place undue reliance on our forward-looking statements, as they are based on the current beliefs and expectations of our management and subject to significant risks and uncertainties, many of which are beyond our control or are subject to change. Although we believe the assumptions upon which we base our forward-looking statements are reasonable, they could be inaccurate. Some of the risks and important factors that could cause actual results to differ from those described in our forward-looking statements can be found in the “Risk Factors” section of our Annual Report on Form 10-K for the year ended Dec. 31, 2019, filed with the Securities and Exchange Commission.

# # #

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SEI INVESTMENTS COMPANY

CONSOLIDATED STATEMENTS OF OPERATIONS

(In thousands, except per share data)

(Unaudited)

						For the Three Months Ended September 30,																		For the Nine Months Ended September 30,
						2020						2019						2020						2019
Asset management, admin. and distribution fees						$339,609						$330,943						$992,039						$969,812
Information processing and software servicing fees						85,318						85,311						248,296						256,848
Total revenues						424,927						416,254						1,240,335						1,226,660
Subadvisory, distribution and other asset mgmt. costs						45,126						44,978						134,645						134,960
Software royalties and other information processing costs						6,992						7,198						21,828						22,719
Compensation, benefits and other personnel						134,795						130,579						391,607						386,913
Stock-based compensation						6,467						5,453						20,458						15,555
Consulting, outsourcing and professional fees						57,949						48,789						168,350						144,325
Data processing and computer related						24,437						22,338						71,647						65,514
Facilities, supplies and other costs						16,679						15,926						47,448						51,771
Amortization						13,200						12,947						39,417						38,407
Depreciation						7,945						7,409						23,058						22,162
Total expenses						313,590						295,617						918,458						882,326
Income from operations						111,337						120,637						321,877						344,334
Net gain (loss) on investments						776						611						(1,310)						2,121
Interest and dividend income						1,009						4,167						5,582						12,737
Interest expense						(153)						(154)						(456)						(477)
Equity in earnings of unconsolidated affiliate						28,305						37,609						86,488						112,758
Income before income taxes						141,274						162,870						412,181						471,473
Income taxes						30,178						30,702						90,777						98,784
Net income						$111,096						$132,168						$321,404						$372,689
Basic earnings per common share						$0.76						$0.88						$2.18						$2.45
Shares used to calculate basic earnings per share						145,812						150,855						147,586						152,009
Diluted earnings per common share						$0.75						$0.86						$2.14						$2.40
Shares used to calculate diluted earnings per share						147,907						154,227						149,958						155,311
Dividends declared per common share						$—						$—						$0.35						$0.33

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SEI INVESTMENTS COMPANY

CONSOLIDATED BALANCE SHEETS

(In thousands)

(Unaudited)

						September 30,						December 31,
						2020						2019
Assets
Current Assets:
Cash and cash equivalents						$767,698						$841,446
Restricted cash						3,101						3,101
Receivables from investment products						51,644						54,165
Receivables, net of allowance for doubtful accounts of $1,310 and $1,201						378,170						340,358
Securities owned						35,820						33,486
Other current assets						38,475						32,289
Total Current Assets						1,274,908						1,304,845
Property and Equipment, net of accumulated depreciation of $370,072 and $353,453						180,531						160,859
Operating Lease Right-of-Use Assets						38,945						42,789
Capitalized Software, net of accumulated amortization of $479,159 and $442,677						278,226						296,068
Available for Sale and Equity Securities						116,564						116,917
Investments in Affiliated Funds, at fair value						5,207						5,988
Investment in Unconsolidated Affiliate						33,117						67,413
Goodwill						64,489						64,489
Intangible Assets, net of accumulated amortization of $11,536 and $8,773						25,225						27,987
Deferred Contract Costs						33,833						30,991
Deferred Income Taxes						2,065						2,822
Other Assets, net						32,507						30,202
Total Assets						$2,085,617						$2,151,370
Liabilities and Equity
Current Liabilities:
Accounts payable						$13,038						$4,423
Accrued liabilities						223,217						272,801
Current portion of long-term operating lease liabilities						8,445						9,156
Deferred revenue						5,815						7,185
Total Current Liabilities						250,515						293,565
Long-term Income Taxes Payable						803						803
Deferred Income Taxes						47,578						55,722
Long-term Operating Lease Liabilities						34,768						38,450
Other Long-term Liabilities						22,520						24,052
Total Liabilities						356,184						412,592
Shareholders' Equity:
Common stock, $0.01 par value, 750,000 shares authorized; 144,491 and 149,745 shares issued and outstanding						1,445						1,497
Capital in excess of par value						1,174,142						1,158,900
Retained earnings						581,244						601,885
Accumulated other comprehensive loss, net						(27,398)						(23,504)
Total Shareholders' Equity						1,729,433						1,738,778
Total Liabilities and Shareholders' Equity						$2,085,617						$2,151,370

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ENDING ASSET BALANCES

(In millions) (Unaudited)

						Sept. 30,						Dec. 31,						Mar. 31,						Jun. 30,						Sept. 30,
						2019						2019						2020						2020						2020
Private Banks:
Equity and fixed-income programs						$22,580						$23,851						$21,160						$22,974						$23,499
Collective trust fund programs						4						4						5						5						6
Liquidity funds						3,695						3,405						4,143						4,291						3,718
Total assets under management						$26,279						$27,260						$25,308						$27,270						$27,223
Client assets under administration						23,985						25,801						21,497						23,903						24,174
Total assets						$50,264						$53,061						$46,805						$51,173						$51,397
Investment Advisors:
Equity and fixed-income programs						$65,059						$67,895						$54,856						$59,958						$65,581
Collective trust fund programs						4						4						2						3						3
Liquidity funds						2,673						2,887						5,969						6,648						3,866
Total assets under management						$67,736						$70,786						$60,827						$66,609						$69,450
Institutional Investors:
Equity and fixed-income programs						$82,659						$84,291						$72,399						$80,257						$83,846
Collective trust fund programs						81						83						94						103						101
Liquidity funds						2,290						1,746						3,672						1,924						2,096
Total assets under management						$85,030						$86,120						$76,165						$82,284						$86,043
Client assets under advisement						4,467						3,948						3,406						3,326						3,618
Total assets						$89,497						$90,068						$79,571						$85,610						$89,661
Investment Managers:
Collective trust fund programs						53,169						58,070						48,226						58,178						63,277
Liquidity funds						477						479						392						664						389
Total assets under management						$53,646						$58,549						$48,618						$58,842						$63,666
Client assets under administration (A)						637,986						657,541						610,794						668,611						730,369
Total assets						$691,632						$716,090						$659,412						$727,453						$794,035
Investments in New Businesses:
Equity and fixed-income programs						$1,621						$1,688						$1,484						$1,498						$1,572
Liquidity funds						132						158						152						194						169
Total assets under management						$1,753						$1,846						$1,636						$1,692						$1,741
Client assets under advisement						825						1,343						1,056						1,193						1,179
Total assets						$2,578						$3,189						$2,692						$2,885						$2,920
LSV Asset Management:
Equity and fixed-income programs (B)						$100,295						$107,476						$70,851						$81,134						$82,051
Total:
Equity and fixed-income programs (C)						$272,214						$285,201						$220,750						$245,821						$256,549
Collective trust fund programs						53,258						58,161						48,327						58,289						63,387
Liquidity funds						9,267						8,675						14,328						13,721						10,238
Total assets under management						$334,739						$352,037						$283,405						$317,831						$330,174
Client assets under advisement						5,292						5,291						4,462						4,519						4,797
Client assets under administration (D)						661,971						683,342						632,291						692,514						754,543
Total assets						$1,002,002						$1,040,670						$920,158						$1,014,864						$1,089,514

(A)Client assets under administration in the Investment Managers segment include $51.1 billion of assets that are at fee levels below our normal full-service assets (as of September 30, 2020).

(B)Equity and fixed-income programs include $1.6 billion of assets managed by LSV in which fees are based on performance only (as of September 30, 2020).

(C)Equity and fixed-income programs include $7.5 billion of assets invested in various asset allocation funds at September 30, 2020.

(D)In addition to the numbers presented, SEI also administers an additional $11.5 billion in Funds of Funds assets (as of

September 30, 2020) on which SEI does not earn an administration fee.

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AVERAGE ASSET BALANCES

(In millions) (Unaudited)

						3rd Qtr.						4th Qtr.						1st Qtr.						2nd Qtr.						3rd Qtr.
						2019						2019						2020						2020						2020
Private Banks:
Equity and fixed-income programs						$22,432						$23,106						$24,657						$22,229						$23,740
Collective trust fund programs						4						4						4						5						7
Liquidity funds						3,625						3,581						3,581						4,366						3,948
Total assets under management						$26,061						$26,691						$28,242						$26,600						$27,695
Client assets under administration						23,717						24,930						24,840						23,819						25,295
Total assets						$49,778						$51,621						$53,082						$50,419						$52,990
Investment Advisors:
Equity and fixed-income programs						$64,761						$66,371						$64,933						$57,429						$64,479
Collective trust fund programs						5						4						3						3						3
Liquidity funds						2,580						2,673						3,284						6,923						4,569
Total assets under management						$67,346						$69,048						$68,220						$64,355						$69,051
Institutional Investors:
Equity and fixed-income programs						$82,398						$83,304						$79,926						$77,037						$82,830
Collective trust fund programs						80						82						86						100						102
Liquidity funds						2,287						2,106						2,342						2,476						2,120
Total assets under management						$84,765						$85,492						$82,354						$79,613						$85,052
Client assets under advisement						3,797						4,106						3,760						3,362						3,565
Total assets						$88,562						$89,598						$86,114						$82,975						$88,617
Investment Managers:
Collective trust fund programs						52,587						55,499						55,952						54,061						62,028
Liquidity funds						460						642						617						482						565
Total assets under management						$53,047						$56,141						$56,569						$54,543						$62,593
Client assets under administration (A)						630,328						646,592						654,386						649,012						713,528
Total assets						$683,375						$702,733						$710,955						$703,555						$776,121
Investments in New Businesses:
Equity and fixed-income programs						$1,609						$1,649						$1,663						$1,468						$1,560
Liquidity funds						142						145						168						182						180
Total assets under management						$1,751						$1,794						$1,831						$1,650						$1,740
Client assets under advisement						842						1,044						1,222						1,148						1,206
Total assets						$2,593						$2,838						$3,053						$2,798						$2,946
LSV Asset Management:
Equity and fixed-income programs (B)						$100,094						$104,814						$88,059						$80,395						$83,536
Total:
Equity and fixed-income programs (C)						$271,294						$279,244						$259,238						$238,558						$256,145
Collective trust fund programs						52,676						55,589						56,045						54,169						62,140
Liquidity funds						9,094						9,147						9,992						14,429						11,382
Total assets under management						$333,064						$343,980						$325,275						$307,156						$329,667
Client assets under advisement						4,639						5,150						4,982						4,510						4,771
Client assets under administration (D)						654,045						671,522						679,226						672,831						738,823
Total assets						$991,748						$1,020,652						$1,009,483						$984,497						$1,073,261

(A)    Average client assets under administration in the Investment Managers segment during third-quarter 2020 include $50.4 billion that are at fee levels below our normal full-service assets.

(B)    Equity and fixed-income programs include $1.6 billion of average assets managed by LSV in which fees are based on performance only during third-quarter 2020.

(C)    Equity and fixed-income programs include $7.5 billion of average assets invested in various asset allocation funds during third-quarter 2020.

(D)    In addition to the numbers presented, SEI also administers an additional $11.4 billion of average assets in Funds of Funds assets during third-quarter 2020 on which SEI does not earn an administration fee.

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