SEI投資公司
MX ˙ BMV ˙ US7841171033
SecurityMX:SEIC / SEI Investments Company
InstitutionNorthern Trust Corp
Latest Disclosed Ownership905,607 shares
Latest Disclosed Value $ 71,062,981
Northern Trust Corp reports 1.59% increase in ownership of SEIC / SEI Investments Company

On May 14, 2026 - Northern Trust Corp filed a 13F-HR form disclosing ownership of 905,607 shares of SEI Investments Company (MX:SEIC) valued at $71,062,981 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 17, 2026 disclosing 891,476 shares of SEI Investments Company. This represents a change in shares of 1.59% during the quarter.

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)
2026-05-14 2026-03-31 13F SEI INVTS COM 784117103 905,607 14,131 1.59 71,063 -2.81 0.0019
2026-02-17 2025-12-31 13F SEI INVTS COM 784117103 891,476 -31,144 -3.38 73,119 -6.60 0.0019
2025-11-14 2025-09-30 13F SEI INVTS COM 784117103 922,620 8,155 0.89 78,284 -4.73 0.0100
2025-08-13 2025-06-30 13F SEI INVTS COM 784117103 914,465 -139,383 -13.23 82,174 0.44 0.0113
2025-05-13 2025-03-31 13F SEI INVTS COM 784117103 1,053,848 -14,333 -1.34 81,810 -7.14 0.0121
2025-02-14 2024-12-31 13F SEI INVTS COM 784117103 1,068,181 184,339 20.86 88,104 44.07 0.0125
2024-11-13 2024-09-30 13F SEI INVTS COM 784117103 883,842 -122,711 -12.19 61,153 -6.08 0.0100
2024-08-14 2024-06-30 13F SEI INVTS COM 784117103 1,006,553 75,719 8.13 65,114 -2.71 0.0110
2024-05-14 2024-03-31 13F SEI INVTS COM 784117103 930,834 -114,347 -10.94 66,927 0.76 0.0116
2024-02-13 2023-12-31 13F SEI INVTS COM 784117103 1,045,181 -98,596 -8.62 66,421 -3.58 0.0120
2023-11-13 2023-09-30 13F SEI INVTS COM 784117103 1,143,777 70,937 6.61 68,890 7.70 0.0133
2023-08-11 2023-06-30 13F SEI INVTS COM 784117103 1,072,840 -24,772 -2.26 63,963 1.26 0.0123
2023-05-15 2023-03-31 13F SEI INVTS COM 784117103 1,097,612 16,159 1.49 63,168 0.19 0.0125
2023-02-13 2022-12-31 13F SEI INVTS COM 784117103 1,081,453 -14,468 -1.32 63,049 17.29 0.0132
2022-11-14 2022-09-30 13F SEI INVTS COM 784117103 1,095,921 -17,389 -1.56 53,754 -10.62 0.0123
2022-08-12 2022-06-30 13F SEI INVTS COM 784117103 1,113,310 -42,364 -3.67 60,141 -13.57 0.0129
2022-05-13 2022-03-31 13F SEI INVTS COM 784117103 1,155,674 -19,819 -1.69 69,583 -2.86 0.0122
2022-02-08 2021-12-31 13F SEI INVTS COM 784117103 1,175,493 -26,438 -2.20 71,634 0.50 0.0117
2021-11-15 2021-09-30 13F SEI INVTS COM 784117103 1,201,931 2,695 0.22 71,275 -4.09 0.0126
2021-08-13 2021-06-30 13F SEI INVTS COM 784117103 1,199,236 -39,933 -3.22 74,316 -1.57 0.0131
2021-05-12 2021-03-31 13F SEI INVTS COM 784117103 1,239,169 48,135 4.04 75,502 10.31 0.0140
2021-02-11 2020-12-31 13F SEI INVTS COM 784117103 1,191,034 -26,301 -2.16 68,448 10.86 0.0133
2020-11-16 2020-09-30 13F SEI INVTS COM 784117103 1,217,335 -45,709 -3.62 61,744 -11.09 0.0135
2020-08-14 2020-06-30 13F SEI INVTS COM 784117103 1,263,044 -43,537 -3.33 69,442 14.69 0.0165
2020-05-14 2020-03-31 13F SEI INVESTMENTS COM 784117103 1,306,581 20,965 1.63 60,546 -28.08 0.0174
2020-02-14 2019-12-31 13F SEI INVESTMENTS COM 784117103 1,285,616 2,336 0.18 84,182 10.71 0.0188
2019-11-13 2019-09-30 13F SEI INVESTMENTS COM 784117103 1,283,280 -26,257 -2.01 76,040 3.50 0.0182
2019-08-13 2019-06-30 13F SEI INVESTMENTS COM 784117103 1,309,537 1,764 0.13 73,466 7.51 0.0174
2019-05-13 2019-03-31 13F SEI INVESTMENTS COM 784117103 1,307,773 18,409 1.43 68,331 14.71 0.0169
2019-02-12 2018-12-31 13F SEI INVESTMENTS COM 784117103 1,289,364 29,895 2.37 59,569 -22.59 0.0167
2018-11-14 2018-09-30 13F SEI INVESTMENTS COM 784117103 1,259,469 -18,001 -1.41 76,953 -3.65 0.0188
2018-09-18 2018-06-30 13F/A-1 SEI INVESTMENTS COM 784117103 1,277,470 -13,516 -1.05 79,866 -17.42 0.0203
2018-08-14 2018-06-30 13F SEI INVESTMENTS COM 784117103 1,287,448 -3,538 80,490
2018-05-09 2018-03-31 13F SEI INVESTMENTS COM 784117103 1,290,986 -43,412 -3.25 96,708 0.85 0.0252
2018-02-14 2017-12-31 13F SEI INVESTMENTS COM 784117103 1,334,398 -56,485 -4.06 95,890 12.91 0.0243
2017-11-13 2017-09-30 13F SEI INVESTMENTS COM 784117103 1,390,883 -25,376 -1.79 84,928 11.50 0.0221
2017-08-11 2017-06-30 13F SEI INVESTMENTS COM 784117103 1,416,259 17,776 1.27 76,167 7.98 0.0213
2017-05-12 2017-03-31 13F SEI INVESTMENTS COM 784117103 1,398,483 21,145 1.54 70,540 3.76 0.0203
2017-02-13 2016-12-31 13F SEI INVESTMENTS COM 784117103 1,377,338 -90,823 -6.19 67,985 1.53 0.0209
2016-11-09 2016-09-30 13F SEI INVESTMENTS COM 784117103 1,468,161 11,263 0.77 66,962 -4.47 0.0209
2016-08-12 2016-06-30 13F SEI INVESTMENTS COM 784117103 1,456,898 -41,612 -2.78 70,092 6.91 0.0228
2016-08-19 2016-03-31 13F/A-1 SEI INVESTMENTS COM 784117103 1,498,510 4,902 0.33 65,559 -16.24 0.0217
2016-05-13 2016-03-31 13F Sei COMM 784117103 1,498,501 64,510
2016-02-12 2015-12-31 13F Sei COMM 784117103 1,493,608 -25,901 -1.70 78,266 6.80 0.0259
2015-11-12 2015-09-30 13F SEI INVESTMENTS COM 784117103 1,519,509 1,519,509 0.00 73,286 0.0245
2015-08-13 2015-06-30 13F Sei COMM 784117103 0 -1,467,734 -100.00 0 -100.00
2015-05-14 2015-03-31 13F Sei COMM 784117103 1,467,734 -15,514 -1.05 64,712 8.96 0.0195
2015-02-12 2014-12-31 13F Sei COM 784117103 1,483,248 1,196 0.08 59,389 10.82 0.0179
2014-11-13 2014-09-30 13F Sei COMM 784117103 1,482,052 -71,377 -4.59 53,590 5.27 0.0168
2014-08-14 2014-06-30 13F SEI INVESTMENTS com 784117103 1,553,429 -22,939 -1.46 50,906 -3.92 0.0159
2014-05-14 2014-03-31 13F SEI INVESTMENTS COMM 784117103 1,576,368 -8,438 -0.53 52,981 -3.74 0.0167
2014-02-21 2013-12-31 13F/A-1 SEI INVESTMENTS COM 784117103 1,584,806 -103,598 -6.14 55,042 5.47 0.0177
2014-02-12 2013-12-31 13F SEI INVESTMENTS COM 784117103 1,584,806 55,042
2013-11-13 2013-09-30 13F SEI INVESTMENTS COM 784117103 1,688,404 155,525 10.15 52,188 19.75 0.0184
2013-08-09 2013-06-30 13F SEI INVESTMENTS COM 784117103 1,532,879 1,532,879 43,579 0.0158
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.