SEI Investments Company
US ˙ NasdaqGS ˙ US7841171033

SecuritySEIC / SEI Investments Company
InstitutionDimensional Fund Advisors Lp
Latest Disclosed Ownership1,873,198 shares
Latest Disclosed Value $ 146,983,892
Dimensional Fund Advisors Lp reports 1.08% increase in ownership of SEIC / SEI Investments Company

On May 7, 2026 - Dimensional Fund Advisors Lp filed a 13F-HR form disclosing ownership of 1,873,198 shares of SEI Investments Company (US:SEIC) valued at $146,989,847 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 12, 2026 disclosing 1,853,144 shares of SEI Investments Company. This represents a change in shares of 1.08% during the quarter. The current value of the position is $162,986,958 USD.

Institutional Ownership: 13F and NPORT Filings

The Security and Class in the table below are shown exactly as filed by the investor. We do our best to track continuity of investments through acquisitions, and this will be reflected in the table as changes in names. In addition to descriptive data, performance of the investment is shown over time. To calculate quarterly performance, we first calculate cost basis of the shares purchased during the quarter, then use that to calculate gross profit. Quarterly return is Gross Profit / Starting Portfolio value.

Note that cost basis is calculated and stored in thousands, so small quarterly changes in shares frequently result in a cost basis of zero.

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Disclosed Equity Positions (from 13F/NPORT Filings)
File
Date		 Effective
Date		Form Security Class ID Avg Price
Paid (Est)		 Reported
Shares		 ΔShares ΔShares
(%)		 Reported
Value
(x1000)		 ΔValue
(%)		 Alloc
(%)		 ΔAlloc ΔAlloc (%) Cost Basis
(x1000)		 Unrealized
Gain/Loss
(x1000)
2026-05-07 2026-03-31 13F SEI INVTS COM 784117103 1,873,198 20,054 1.08 146,984 -3.30 0.0066
2026-02-12 2025-12-31 13F SEI INVTS COM 784117103 1,853,144 -9,908 -0.53 152,003 -3.85 0.0319
2025-11-12 2025-09-30 13F SEI INVTS COM 784117103 1,863,052 31,953 1.75 158,084 -3.93 0.0339
2025-08-12 2025-06-30 13F SEI INVTS COM 784117103 1,831,099 98,588 5.69 164,543 22.35 0.0381
2025-05-13 2025-03-31 13F SEI INVTS COM 784117103 1,732,511 111,065 6.85 134,487 0.56 0.0334
2025-02-13 2024-12-31 13F SEI INVTS COM 784117103 1,621,446 -14,345 -0.88 133,740 18.16 0.0321
2024-11-07 2024-09-30 13F SEI INVTS COM 784117103 1,635,791 255,480 18.51 113,181 26.75 0.0275
2024-08-09 2024-06-30 13F SEI INVTS COM 784117103 1,380,311 222,631 19.23 89,291 7.27 0.0233
2024-05-10 2024-03-31 13F SEI INVTS COM 784117103 1,157,680 -7,222 -0.62 83,237 12.44 0.0225
2024-02-07 2023-12-31 13F SEI INVTS COM 784117103 1,164,902 -12,869 -1.09 74,032 4.36 0.0216
2023-11-09 2023-09-30 13F SEI INVTS COM 784117103 1,177,771 -4,355 -0.37 70,939 0.65 0.0233
2023-08-09 2023-06-30 13F SEI INVTS COM 784117103 1,182,126 4,312 0.37 70,478 3.98 0.0225
2023-05-12 2023-03-31 13F SEI INVTS COM 784117103 1,177,814 3,873 0.33 67,779 99,573.53 0.0228
2023-02-09 2022-12-31 13F SEI INVTS COM 784117103 1,173,941 17,685 1.53 68 -99.88 0.0202
2022-11-10 2022-09-30 13F SEI INVTS COM 784117103 1,156,256 22,179 1.96 56,724 -7.41 0.0218
2022-08-12 2022-06-30 13F SEI INVTS COM 784117103 1,134,077 37,938 3.46 61,262 -7.19 0.0220
2022-05-13 2022-03-31 13F SEI INVTS COM 784117103 1,096,139 12,447 1.15 66,006 -0.05 0.0203
2022-02-09 2021-12-31 13F SEI INVTS COM 784117103 1,083,692 4,928 0.46 66,042 3.23 0.0200
2021-11-12 2021-09-30 13F SEI INVTS COM 784117103 1,078,764 7,626 0.71 63,977 -3.62 0.0206
2021-08-12 2021-06-30 13F SEI INVTS COM 784117103 1,071,138 25,620 2.45 66,378 4.08 0.0210
2021-05-14 2021-03-31 13F SEI INVTS COM 784117103 1,045,518 15,618 1.52 63,779 7.76 0.0211
2021-03-08 2020-12-31 13F/A-2 SEI INVTS COM 784117103 1,029,900 18,453 1.82 59,185 15.37 0.0214
2021-02-11 2020-12-31 13F SEI INVTS COM 784117103 1,029,900 18,453 59,185 21,374.4761
2020-11-12 2020-09-30 13F SEI INVTS COM 784117103 1,011,447 21,278 2.15 51,302 -5.74 0.0218
2020-08-13 2020-06-30 13F SEI INVTS COM 784117103 990,169 45,052 4.77 54,427 24.27 0.0239
2020-05-14 2020-03-31 13F SEI INVESTMENTS COM 784117103 945,117 -43,926 -4.44 43,796 -32.37 0.0228
2020-02-14 2019-12-31 13F SEI INVESTMENTS COM 784117103 989,043 -24,480 -2.42 64,763 7.84 0.0236
2019-11-12 2019-09-30 13F SEI INVESTMENTS COM 784117103 1,013,523 -78,702 -7.21 60,056 -1.98 0.0233
2019-08-13 2019-06-30 13F SEI INVESTMENTS COM 784117103 1,092,225 -2,416 -0.22 61,271 7.13 0.0238
2019-08-12 2019-03-31 13F/A-2 SEI INVESTMENTS COM 784117103 1,094,641 228,163 26.33 57,195 42.88 0.0228
2019-05-10 2019-03-31 13F SEI INVESTMENTS COM 784117103 1,094,641 228,163 57,195
2019-02-26 2018-12-31 13F/A-1 SEI INVESTMENTS COM 784117103 866,478 349,016 67.45 40,030 26.61 0.0181
2019-02-13 2018-12-31 13F SEI INVESTMENTS COM 784117103 866,478 349,016 40,030
2018-11-13 2018-09-30 13F SEI INVESTMENTS COM 784117103 517,462 684 0.13 31,618 -2.14 0.0120
2018-08-10 2018-06-30 13F SEI INVESTMENTS COM 784117103 516,778 7,104 1.39 32,311 -15.37 0.0129
2018-05-11 2018-03-31 13F SEI INVESTMENTS COM 784117103 509,674 3,756 0.74 38,180 5.01 0.0159
2018-02-12 2017-12-31 13F SEI INVESTMENTS COM 784117103 505,918 5,367 1.07 36,357 18.95 0.0151
2017-11-13 2017-09-30 13F SEI INVESTMENTS COM 784117103 500,551 6,753 1.37 30,565 15.09 0.0134
2017-08-11 2017-06-30 13F SEI INVESTMENTS COM 784117103 493,798 5,752 1.18 26,557 7.89 0.0123
2017-05-12 2017-03-31 13F SEI INVESTMENTS COM 784117103 488,046 9,155 1.91 24,616 4.13 0.0118
2017-02-09 2016-12-31 13F SEI INVESTMENTS COM 784117103 478,891 -941 -0.20 23,639 8.02 0.0118
2016-11-10 2016-09-30 13F SEI INVESTMENTS COM 784117103 479,832 27,459 6.07 21,884 0.57 0.0118
2016-08-09 2016-06-30 13F SEI INVESTMENTS COM 784117103 452,373 1,236 0.27 21,759 12.04 0.0125
2016-05-13 2016-03-31 13F SEI INVESTMENTS COM 784117103 451,137 10,842 2.46 19,421 -15.83 0.0116
2016-02-10 2015-12-31 13F SEI INVESTMENTS COM 784117103 440,295 15,453 3.64 23,073 12.62 0.0144
2015-11-13 2015-09-30 13F SEI INVESTMENTS COM 784117103 424,842 6,741 1.61 20,487 -0.06 0.0134
2015-08-14 2015-06-30 13F SEI INVESTMENTS COM 784117103 418,101 22,753 5.76 20,499 17.61 0.0126
2015-05-14 2015-03-31 13F SEI INVESTMENTS COM 784117103 395,348 230 0.06 17,430 10.16 0.0110
2015-02-06 2014-12-31 13F SEI INVESTMENTS COM 784117103 395,118 28,235 7.70 15,822 19.26 0.0104
2014-11-13 2014-09-30 13F SEI INVESTMENTS COM 784117103 366,883 -17,483 -4.55 13,267 5.34 0.0094
2014-08-08 2014-06-30 13F SEI INVESTMENTS COM 784117103 384,366 14,414 3.90 12,594 1.29 0.0088
2014-05-14 2014-03-31 13F SEI INVESTMENTS COM 784117103 369,952 8,700 2.41 12,434 -0.89 0.0093
2014-02-12 2013-12-31 13F SEI INVESTMENTS COM 784117103 361,252 -3,776 -1.03 12,546 11.20 0.0098
2013-11-13 2013-09-30 13F SEI INVESTMENTS COM 784117103 365,028 5,275 1.47 11,282 10.31 0.0098
2013-08-15 2013-06-30 13F SEI INVESTMENTS COM 784117103 359,753 359,753 10,228 0.0096
Legend
Shares
The total number of shares held by the institution at the end of the reporting period (the effective date). This is provided in the filing.
Value
The total value of the shares as of the effective date. This is provided in the filing.
Avg. Share Price
The weighted average share price of the shares held by the institution. We use FIFO accounting to determine this price
Class
This is the security class as indicated by the filer. There are a variety of values for this field. Common values include "EC" = equity common, "EP" - equity preferred
Allocation (%)
The percent of the institution's portfolio that this position represents. This is provided in NPORT filings. For 13F filings, we calculate it.
Change in Allocation
The change in allocation from the prior reporting period. This is calculated as current allocation - prior allocation.
Change in Allocation (%)
The percent change in allocation from the prior reporting period. This is calculated as (current allocation - prior allocation) / prior allocation.
Cost Basis
The total cost of the shares held. This is calculated as reported shares * avg. share price
Unrealized Gain/Loss
This is the market value of the position as of the effective date minus the cost basis.