SEI Investments Company
MX ˙ BMV ˙ US7841171033
SecurityMX:SEIC / SEI Investments Company
InstitutionBanco Santander, S.A.
Latest Disclosed Ownership47,549 shares
Latest Disclosed Value $ 3,731,170
Banco Santander, S.A. ownership in SEIC / SEI Investments Company

On May 8, 2026 - Banco Santander, S.A. filed a 13F-HR form disclosing ownership of 47,549 shares of SEI Investments Company (MX:SEIC) valued at $3,731,170 USD as of March 31, 2026. The entity filed a previous 13F-HR on February 13, 2026 disclosing 47,549 shares of SEI Investments Company. This represents a change in shares of 0.00% 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)
2026-05-08 2026-03-31 13F SEI INVTS COM 784117103 47,549 0 0.00 3,731 -4.31 0.0301
2026-02-13 2025-12-31 13F SEI INVTS COM 784117103 47,549 -16,371 -25.61 3,900 -28.10 0.0292
2025-11-12 2025-09-30 13F SEI INVTS COM 784117103 63,920 0 0.00 5,424 -5.57 0.0482
2025-08-01 2025-06-30 13F SEI INVTS COM 784117103 63,920 -43,547 -40.52 5,744 -31.16 0.0545
2025-05-09 2025-03-31 13F SEI INVTS COM 784117103 107,467 65,897 158.52 8,343 143.35 0.0921
2025-02-07 2024-12-31 13F SEI INVTS COM 784117103 41,570 -730 -1.73 3,429 17.16 0.0413
2024-11-12 2024-09-30 13F SEI INVTS COM 784117103 42,300 -2,600 -5.79 2,927 0.76 0.0345
2024-07-29 2024-06-30 13F SEI INVTS COM 784117103 44,900 -2,260 -4.79 2,905 -14.34 0.0360
2024-05-10 2024-03-31 13F SEI INVTS COM 784117103 47,160 -9,540 -16.83 3,391 -5.91 0.0409
2024-02-09 2023-12-31 13F SEI INVTS COM 784117103 56,700 -6,120 -9.74 3,603 -4.76 0.0426
2023-11-08 2023-09-30 13F SEI INVTS COM 784117103 62,820 -2,860 -4.35 3,784 -3.37 0.0536
2023-08-14 2023-06-30 13F SEI INVTS COM 784117103 65,680 -16,160 -19.75 3,916 -16.86 0.0514
2023-05-10 2023-03-31 13F SEI INVTS COM 784117103 81,840 -11,210 -12.05 4,710 -13.18 0.0705
2023-02-13 2022-12-31 13F SEI INVTS COM 784117103 93,050 -8,577 -8.44 5,425 8.81 0.0815
2022-11-08 2022-09-30 13F SEI INVTS COM 784117103 101,627 -1,003 -0.98 4,985 -10.08 0.0665
2022-07-28 2022-06-30 13F SEI INVTS COM 784117103 102,630 0 0.00 5,544 -10.28 0.0739
2022-05-09 2022-03-31 13F SEI INVTS COM 784117103 102,630 19,540 23.52 6,179 22.02 0.0663
2022-02-09 2021-12-31 13F SEI INVTS COM 784117103 83,090 6,000 7.78 5,064 10.79 0.0273
2021-11-08 2021-09-30 13F SEI INVTS COM 784117103 77,090 0 0.00 4,571 -4.31 0.0246
2021-07-29 2021-06-30 13F SEI INVTS COM 784117103 77,090 12,040 18.51 4,777 20.54 0.0267
2021-05-10 2021-03-31 13F SEI INVTS COM 784117103 65,050 11,460 21.38 3,963 28.67 0.0279
2021-02-12 2020-12-31 13F SEI INVTS COM 784117103 53,590 8,030 17.63 3,080 33.28 0.0221
2020-11-09 2020-09-30 13F SEI INVTS COM 784117103 45,560 7,290 19.05 2,311 9.84 0.0304
2020-08-05 2020-06-30 13F SEI INVTS COM 784117103 38,270 3,050 8.66 2,104 28.92 0.0273
2020-05-11 2020-03-31 13F SEI INVESTMENTS COM 784117103 35,220 2,440 7.44 1,632 -23.95 0.0187
2020-02-07 2019-12-31 13F SEI INVESTMENTS COM 784117103 32,780 2,800 9.34 2,146 20.29 0.0198
2019-11-06 2019-09-30 13F SEI INVESTMENTS COM 784117103 29,980 -1,670 -5.28 1,784 0.79 0.0174
2019-08-07 2019-06-30 13F SEI INVESTMENTS COM 784117103 31,650 3,700 13.24 1,770 22.58 0.0180
2019-05-13 2019-03-31 13F SEI INVESTMENTS COM 784117103 27,950 0 0.00 1,444 11.85 0.0163
2019-02-12 2018-12-31 13F SEI INVESTMENTS COM 784117103 27,950 4,620 19.80 1,291 -9.40 0.0163
2018-11-13 2018-09-30 13F SEI INVESTMENTS COM 784117103 23,330 23,330 1,425 0.0163
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.